No company can do this without at some point causing controversy, perhaps because the models caused outrage or, in a broader sense of the term, or because they provoked discussion among people with significantly contrasting opinions. Here are 40 cases where controversy of some sort arose, presented in chronological order:

The Series M is sometimes known, because of its engine, as the Copper-Cooled, which adds little more than confusion. In fact, the 2.2-litre four-cylinder unit was air-cooled, but its cooling fins were made of copper, which was cheaper and easier to work with than other metals which might have been chosen instead.

As with all engines of this type, the whole point was that it would be both lighter and cheaper to build because there was no water system. So few cars were built before the project was abandoned that this was not a major controversy in public (though owners were no doubt cross about it), but it certainly created quite a fuss within the company.

Chevrolet had got the hang of air-cooled engines by the time it brought out the Corvair. This car nevertheless became a poster child for automotive controversy due to the mounting of its engine behind the rear wheels and the use of swing-axle rear suspension, neither of which helped its stability.

The Corvair was heavily criticised by Ralph Nader (born 1934) in his book Unsafe at Any Speed. By the time this was published in 1965, Chevrolet had already updated the car with more suitable suspension, but public confidence in it soon collapsed as a result of the devastatingly bad publicity.

Front-wheel drive was hardly new to the American motor industry when the Toronado arrived, but it hadn’t been used since the 1930s, and certainly not in conjunction, as in this case, with a 7.0-litre V8 engine (later extended to 7.5 litres).

It seemed like an odd, perhaps even fearful, combination, but the initially controversial Toronado would soon be seen as a trailblazer. Within a decade, its layout would be so common among large American cars as to be no longer worth mentioning.

The original GT was a quite startling car for Opel to produce. The available engines, measuring 1.1 or 1.9 litres, were conventional, but it would have been difficult to predict that GM’s German brand would come up with an elegant, swoopy coupe with pop-up headlights.

Opel soon backed away from this sort of extravagance, and did not come up with a direct replacement after GT production came to an end in 1973. It would not create anything so radical again for nearly three decades.

The eighth-generation Eldorado, launched one year after the Oldsmobile Toronado, shared that car’s front-wheel drive layout, but in one respect Cadillac went a stage further. In 1970, the Eldorado became available with an 8.2-litre V8 engine, beating its own previous record of 7.7 litres.

How controversial this was depended on where you lived. In Europe, where any manufacturer which tried it would have been suspected of sniffing glue, putting the power of such a monster motor through the front wheels seemed like madness. In North America, where very different driving conditions applied, it made perfect sense. Cadillac continued to use the powertrain throughout the ninth generation, abandoning it only when the downsized tenth arrived in 1979.

From the 1971 to the 1973 model years, the already large and intimidating Riviera was made to look even more aggressive, with a V-shaped nose, a complex (for the time) rear window and a massive back end known as the boat tail. Half a century later, its design is still spoken of in hushed tones.

Bill Mitchell (1912-1988), then GM’s Vice President of Design, wanted this Riviera to look controversial, but the man actually responsible for it was Jerry Hirshberg (1940-2019), who later went on to work for Nissan. Understating the case considerably, Hirshberg was quoted as saying, “The car looked slightly eccentric, but so would a Corvette if it were the size of a Cadillac.”

Initially praised for its design, the Vega very quickly developed a reputation for unreliability. In May 1972, it was reported that six out of every seven then built had been recalled due to the risk of either fire or a sticking throttle, or in some cases no doubt both. A further recall, relating to rear axle failure, was issued two months later.

In complete contrast, a limited-production high-performance version called the Cosworth Vega (pictured) was rated extremely highly by the US media of the time, even though it was startlingly expensive.

On the whole, there was little about the ‘72 Torana to cause offence, but one version was so controversial that it was canned before production began. Powered by a 5.0-litre V8 engine with a reputed output of around 400bhp, it was a homologation special intended for use in a class of Australian racing which required only 200 examples to be built.

This didn’t happen, because the Torana was one of three cars (the others being similar versions of the Ford Falcon and Chrysler Valiant Charger) caught up in what has become known as the supercar scare. An article about these proposed monsters stirred up a political storm which led to all three manufacturers cancelling their projects within d

What is a Mazda doing in this story about GM? Well, read on: The Roadpacer was a badge-engineered Holden HJ Premier, which GM built for Mazda, in its pre-Ford alliance days. While the Holden packed traditional straight-six and V8 iron, this was of course far too simple for Hiroshima, which kitted it out with a torqueless 1.3-litre rotary engine (a longtime Mazda obsession) when the bodies arrived from Australia. AP stood for Anti Pollution, but a heavy 1575kg combined with gutless power meant horrendous fuel consumption and it was generally a disaster; just 800 were sold over two years.

The US Chevette was part of GM’s T-car range which also included another model of the same name sold in Brazil, the German Opel Kadett, the British Vauxhall Chevette and the Japanese Isuzu Gemini. Initially, there were no plans to sell it in North America, but changed rapidly in the wake of the 1973 oil crisis.

Even at its launch, and certainly during its production life, media reaction to this Chevette ranged from tepid to hostile, and its reputation has not improved since then. But it was the right car for its time, and remained popular even when rear-wheel drive was coming to be seen as anachronistic in the sub-compact class. According to GM, US sales peaked at a remarkable 451,161 in 1980, and were within 18,000 of that in the following year.

One of the engine options for the ‘77 Delta 88 was a 5.7-litre V8. This was usually Oldsmobile’s own Rocket, but sometimes a Chevrolet small-block would be fitted instead. You might not think anything controversial was going on here, but an owner who found out about it (because parts ordered by a mechanic wouldn’t fit) decided this was an unacceptable policy, and called in the lawyers.

GM was ordered to pay $550 in compensation to anyone who had bought a Chevy-powered Olds before the story broke. For the 1978 model year, Oldsmobile included a page in its brochure clearly stating which brand produced every engine it used, and where it was built.

The second-generation Custom Cruiser was one of the earliest cars fitted with a 5.7-litre diesel V8 engine developed by Oldsmobile and used by many other GM brands. High noise levels and poor performance aside, its fuel economy was very appealing in a decade of high oil prices and increasingly stringent exhaust emissions legislation.

But there were problems in the new engine: a fault could cause water to enter the fuel system, and in addition the cylinder head bolts developed for use in gasoline-engines couldn’t cope with the high compression ratios typical of diesels, leading to catastrophic failures. These matters were eventually resolved, but by then the V8’s reputation had been trashed.

Vauxhall’s Chevette was the British version of the GM T-car, and closely related to the Opel Kadett. Most versions used by 1.3-litre engines, but the HS and later HSR homologation specials were fitted with the brand’s familiar 2.3-litre slant-four engine, which now had a 16-valve cylinder head. Well, actually, two of them, though obviously never in the same car at the same time. One was developed by Vauxhall itself, but the other came from Lotus.

Vauxhall initally used the Lotus head in international rallying, thinking it was legal to do so. In fact, a recent change of rules meant that it wasn’t, and the car was forbidden from competing in this form. The resulting monumental fuss died down only when Vauxhall fitted its own head, which was perfectly legal.

The front end of the second Seville looked conventional enough, but this could not be said of its ‘bustle back’ rear, inspired, it’s said, by Hooper-bodied Rolls-Royces of the 1950s. It was certainly influential (the seventh-generation Lincoln Continental and Chrysler’s sixth-generation Imperial, both launched in the early 1980s, had similar arrangements) but even today opinions on the subject are polarised.

The Seville was also controversial in a completely different way. Two of the available engines were the previously-mentioned Oldsmobile V8 diesel and Cadillac’s own V8-6-4. Both were wildly problematic, though not for the same reasons; more on the latter in a moment...

1981 model pictured

Chevrolet’s first front-wheel drive model was a massive hit in its debut year. More than 800,000 were sold in the US, perhaps partly because it had been reviewed very favourably. It later became clear that the Citations driven by journalists had been heavily reworked, and did not have the torque steer which bedevilled the customer cars.

This, along with poor build quality and a tendency to lock the rear wheels under braking, were among the Citation’s many problems. By the 1985 model year, the last for the car before it was discontinued, sales were well under a tenth of their original figure, and owners who had bought their examples earlier in the run were not happy.

At the start of the 1980s Cadillacs were large, heavy, and powered by lazy V8 engines. Which was a problem as fuel prices had soared, and the brand’s European rivals were usually more svelte and comparatively more economical. GM’s response was the V8-6-4 engine, bravely placed into Caddy’s entire 1981 range (apart from the diesel option). The name indicated that it could run on different numbers of cylinders according to how much power was required in any given situation.

Cylinder deactivation wasn’t new. It had been around since 1908, though back then it was achieved by shutting off carburettors. Cadillac’s system was electronic, and it was so unsuccessful that the engine was abandoned after a single model year. Today, automotive electronics are easily capable of coping with varying the number of cylinders used, but back in 1981 microprocessors were simply too slow.

The Cimarron was Cadillac’s attempt to attract buyers who would not previously have been able to afford any of its models. Based on the global GM J-body platform, it was a close relative of the Holden Camira, Oldsmobile Firenza, Opel Ascona, Pontiac Sunbird and Vauxhall Cavalier, among others, but was priced far higher than any of its US-market counterparts.

As Aston Martin would later find with the Cygnet (a glitzed-up and enormously expensive version of the Toyota iQ city car), putting a fancy badge on a mainstream model and charging lots of money for it was no route to alchemy. The Cimarron failed to excite customers the way Cadillac hoped it would, and was dropped after the 1988 model year.

From 1977 until 1993, Pontiac produced a 2.5-litre four-cylinder engine called the Iron Duke, which was used in many GM cars and pickups, and also in the Grumman LLV mail truck. For several years it was also the base engine in the third-generation Camaro – an unlikely choice, since its sub-100bhp power output gave the car a 0-60mph time of a rather dismal 20 seconds.

The Iron Duke was also used in the Pontiac Firebird, with similarly feeble results, but this does not appear to have enraged GM sports car fans to quite the same extent. As you’re reading this, nearly four decades after it was dropped from the range, somebody somewhere is still shaking their fist at Chevrolet for having had the audacity to put it in the Camaro.

The Fiero was a unique case of a 1980s American mass-market mid-engined two-seat sports car. It was also affordable and, since most of the components were taken from existing models, it was mostly reliable.

Its reputation took a big hit early on, when it became clear that it wasn’t as sporty as it looked, and that it had a habit of catching fire. Later versions were better, and less combustible, but by the time they arrived the public had become very cautious. Fiero production was brought to a halt in August 1988.

The eleventh-generation was conceived at a time when it was feared that fuel prices in the US were about to skyrocket once again, and that nobody would therefore be prepared to buy a large luxury car. It was therefore much smaller than the tenth, which was itself much smaller than the ninth.

The fuel price catastrophe didn’t happen, so Cadillac was left with an unnecessarily compact flagship model. Potential buyers shrugged and went in search of something else.

The second-generation Elan was the only sports car introduced by Lotus during the company’s brief period of GM ownership. It was named after a famous model which had made its debut in 1962, but was almost completely different, most notably because its 1.6-litre Isuzu engine drove the front wheels rather than the rears.

This radical step did not go down well among people who believed that FWD was the work of the devil, but in fact the Elan quickly gained a reputation for excellent handling. Lotus continued building it until 1995, when it sold the production rights to Kia.

The Calibra was regarded with distaste in the UK on the basis that it was mechanically identical to the contemporary Vauxhall Cavalier (sold in other markets as the Opel, Holden or Chevrolet Vectra). How much of a problem this was depended on what you thought of the Cavalier, but there was no doubt that its coupe derivative was an exceptionally good-looking car.

It was also remarkably aerodynamic. Its drag coefficient could be as low as 0.26 – an almost unbelievable figure at the time and still very impressive today – though this applied only to the base model.

The Lotus versions of GM Europe’s full-size saloon were built as standard 3000 GSI 24v models at the Opel factory in Rüsselsheim and then transported to Lotus in Norfolk, where they were completely rebuilt. The process included raising the straight-six engine’s capacity to 3.6 litres and adding twin turbochargers. With the highest-octane pump fuel available, it was then capable of producing 377bhp.

This is not an enormously high figure today, but it was considered horrifying three decades ago, even though the improvements in the car’s braking and suspension were if anything still more impressive. The controversy reached the point where there were calls in the UK for the Lotus Carlton to be banned, though they never came to anything.

Of all today’s General Motors brands, GMC is the one most associated with building trucks. At first sight, the Syclone pickup was wildly inadequate, since it came with a warning that the drivetrain and suspension might be damaged if it had to carry a load of over 500 pounds.

This might have caused widespread outrage if it hadn’t been for the Syclone’s party trick. With a turbocharged 4.3-litre V6 engine producing 280bhp and driving all four wheels, it was found in independent testing to be quicker over a standing quarter-mile than a Ferrari 348ts, even though it cost only slightly more than one fifth as much. And if you wanted more load-carrying ability you could always buy a GMC Sonoma, which was more or less the same thing, only slower.

GM was not originally responsible for the Hummer, which was the civilian version of the Humvee military vehicle, but it bought the marketing rights and applied the H1 name a few years after production began.

It’s reasonably safe to say that nobody who bought an H1 actually needed it, and there were people who wished it didn’t exist at all. It was huge, it was monstrously heavy, it used a phenomenal amount of fuel, and woe betide anyone knocked over by one. On the other hand, actor and politician Arnold Schwarzenegger liked it, and you don’t argue with Arnie.

Manufactured by Opel, which called it the Vectra B, this was the replacement for the series of cars known in the UK as Cavalier. Vauxhall tried to convince members of the press that the new title signified how different the new car was, but in fact it was far closer to the third Cavalier than any two generations of Cavalier were to each other. The name change was simply a matter of GM Europe policy.

It was also regarded as inferior in many respects. A high-ranking Opel employee, whose anonymity we will preserve, said later that it went on sale at least a year before the engineers believed it was ready. Sure enough, improvements made to the car in 1996 made it noticeably better than it had been before.

The EV1 was not GM’s first electric vehicle, but it was the first designed from scratch to run only on battery power, rather than being a conversion of something else. Cars were leased to customers, and in most cases were taken back and destroyed when the programme ended.

GM said it wasn’t possible to make the car profitable, and the car’s initial range of 70-100 miles didn’t exactly impress either. GM was more or less accused of sabotaging the development of EVs in general. How strange it seems now. Then-CEO Rick Wagoner has recently admitted his great regret over the canning of the EV1 programme, which conceivably could have given GM a jump-start into the EV-age.

Unlike its closest rivals, GM Europe took the easy route into the large MPV market in the 1990s by simply repurposing the Chevrolet Venture and adding more Euro-familiar badges. The result was something which had plenty of room and lots of equipment, which was a good start.

However, the Sintra was very heavily criticised in a Euro NCAP crash test report (which included the word ‘fatal’ twice), and placed 182nd out of 182 in a J.D. Power customer satisfaction survey. There was no coming back from that, so GM withdrew one of the most disappointing models it had ever sold in Europe in 1999.

Having already established, with the Cimarron, that reworking a European model for the North American market wasn’t necessarily a good idea, Cadillac tried to disprove its own point 15 years later by introducing the Catera. This was created by rebadging and mildly redesigning the Vauxhall/Opel Omega, and describing it in ads as ‘the Caddy that zigs’ – like that was going to help.

Poor sales persuaded Cadillac to abandon production in Germany after the 2001 model year. The Catera was indirectly replaced in 2003 by the much better – and home-grown - CT-S.

Not since the Opel GT had GM Europe come up with anything as radical as this. It was essentially a second-generation Lotus Elise, which GM partly funded (because Lotus couldn’t afford to) in return for Vauxhall/Opel having the rights to develop and market its own version.

The GM cars were structurally the same as the Elise, but had their own 2.2-litre engines and manual transmissions, mounted at the rear rather than, in the case of Astras and Vectras, at the front. A turbocharged 2.0-litre version was introduced later. Impressive as they were, the cars didn’t really fit into the Vauxhall or Opel ranges, and were dropped after five years.

It’s agreed by many that the Aztek was a pretty practical mid-sized crossover SUV that in some ways was ahead of its time. There’s rarely much reason for a vehicle of this type to be controversial, but the Aztek easily achieved that status because of its appearance, about which almost nobody has a good word to say.

Poor sales can be blamed almost entirely on this. The Aztek’s corporate cousin, the Buick Rendezvous, wasn’t exactly pretty either, but it was far less offensive, and found more customers in its second worst year than the Aztek did in its best. And yet, because of the way these things work, the Aztek is by far the more famous of the two today.

The SSR was, and still is, criticised for being a combination of a pickup, a convertible and a retro hotrod. Visually similar to, or at least not entirely unlike, the Chevy Advance Design trucks of 1947-1955, it was powered at first by a 5.3-litre V8 engine, which was replaced after two years by a 6.0-litre.

Neither the straightline performance nor the handling were especially good, but they were never going to be. The SSR’s most significant feature was its appearance, and more than 20,000 people were sufficiently entranced by that to spend their hard-earned dollars on it.

The Signum was perhaps a cause of bewilderment rather than outright controversy. Based on the Vectra, it had elements of an estate, a hatchback and an MPV, without being definitely any one of these. Vauxhall said, not very convincingly, that it had “created a new car class all its own”, which didn’t help much.

It was roomy and practical, and had a tremendous number of storage spaces, but it never really caught on, perhaps because it was so difficult to describe. GM stopped production in 2008, and did not come up with a direct replacement

Although the BLS was a fairly conventional car in its own right, it was also one of Cadillac’s strangest models. No other Caddy could be described, with some accuracy, as a Vauxhall/Opel Vectra built by Saab and powered (at least in the case of the diesel versions) by a Fiat engine.

It was never sold in North America, and barely registered with buyers in Europe, where Cadillac has never been well known. Production fizzled out in 2009.

The Cobalt was a mainstream compact car which, you would think, should not have been controversial. In fact, it was subject to several recalls, the most serious of which centred on the fact that the ignition key could easily be knocked out of position, shutting off the engine and disabling the power steering, braking assistance and airbags.

The problem, and GM’s reaction to it, became one of the company’s most serious and heavily criticised issues of the 21st century. It also affected other cars based on the same platform, including the Pontiac G5.

In 2001, the first-generation Zafira MPV became available in OPC form (known in the UK as GSi Turbo) with a forced-induction 2.0-litre engine which produced 192bhp. For a car of this type, it was very lively, but not nearly as lively as its successor, which arrived four years later.

The power output had now jumped to 237bhp, and although there was enough grip and braking to cope with that, the Zafira’s high centre of gravity (compared with that of the Astra VXR with the same engine) could lead to interesting moments. There was also the question of whether anyone would want to buy a seven-seater with such high performance, though of course a few people did.

Almost everything about Saab was controversial in the final years of the brand. The last model built in its home country of Sweden was the second-generation 9-5, which had to be truly spectacular to give Saab any hope of survival.

Media reviews were friendly, but not particularly enthusiastic. It was clear that the 9-5 wasn’t good enough and prematurely released. By the time it went on sale, GM had already sold Saab (though the car was developed during its ownership), and the end wasn’t far off.

The first-generation Volt – sold in Australia as a Holden and in Europe as the Vauxhall/Opel Ampera – was known before it went on sale to be a range-extended electric vehicle, with a small petrol engine which recharged the batteries when necessary. In 2010, once a patent had been granted, GM felt free to add that in certain circumstances the engine would partly contribute to driving the car.

The resulting fuss saw GM accused of fibbing about the car, which was now believed in some quarters to be a hybrid rather than a true EV, even though it could not run, as hybrids can, with only the engine operating. The point is now moot, since GM no longer builds either that Volt or the one which replaced it in 2016.

The 9-4X was a crossover SUV developed and built by GM but sold to the public by Saab’s new owner, the Dutch Spyker company. Although it had recognisably Saab-like styling, it was essentially the corporate cousin of the second-generation Cadillac SRX, and like that vehicle it was manufactured in Mexico.

Shortly after its launch, the story came out that Saab ownership might be transferred to China. This never in fact happened, but GM, fearing that it might end up supplying cars to a rival in a very important market, pulled out of the deal. The 9-4X was therefore not only the last new Saab, but one of the very rarest models in the brand’s history.

After being discontinued in 2010, Hummer has re-emerged as a sub-brand of GMC. The first model of the new era is the all-electric EV Pickup, which at first glance seems to tick several environmentally friendly boxes.

But there are concerns. One is that the EV is considerably larger than the old Hummer H1. Another is that, in its most extreme form, it has a power output of around 1000bhp. The combination has led to concerns about safety, though since fewer than a thousand have yet been sold this is so far a matter of prediction rather than information.