Yahoo Autos 
10 most disappointing cars of 2011
What were they thinking?
News item: BMW's top U.S. sales executive says he is disappointed in the 5 Series GT, Automotive News reports. "The disappointment I have is that I thought a lot of our 5-series station wagon customers would go with the GT," Jim O'Donnell says. "In point of fact, that is not happening. We have lost those customers to the competition -- mainly to Mercedes-Benz.
MORE AT CNNMONEY.COM
With its ungainly lift back and high load floor, the 5 Series GT produced a lot of comments along the lines of "What were they thinking?" when it was introduced two years ago, but now it is official: Even BMW makes mistakes.
Designing and engineering new models is part art, part science: a billion-dollar bet on what the car buying public will want for years into the future. The deepest pitfalls come in trying to head off in a new direction, like a convertible minivan or an SUV with a coupe body. Despite all the market research, focus groups, and educated guesses, car companies can get it wrong. The design fails to catch hold, the market doesn't develop, competition proves stronger than expected. Bottom line: They blew it.
Herewith, ten of the biggest mistakes currently on the market:
BMW X6
The X6 is marketed as a "sports activity coupe" that combines the attributes of an SUV (high ground clearance, all wheel drive large wheels and tires) with the stance of a coupé (bold styling, dramatic sloping roof). BMW sales are hot, but buyers are apparently confused by the concept, put off by the chunky styling, or deterred by the high price -- close to $100,000 for the turbocharged M version. So far this year, BMW has sold just 1,559 of them versus more than 10,000 of the more conventional X5.
Mercedes-Benz R-Class
Similar woes have afflicted the Mercedes-Benz R-Class, first introduced in 2006. Essentially a low-roofed minivan with three rows of seats, it was initially marketed as a "sports cruiser." When that didn't fly, Mercedes tied on a more apropos "family tourer" moniker. Confused buyers, put off by the R's funereal looks, stayed away. U.S. sales never came within shouting distance of Mercedes' goal of 25,000 a year. Despite healthy incentives, the round-roofed R-Class has remained anchored to dealers' lots. A scant 195 found buyers during the month of April.
Ford Flex / Lincoln MKT
A valiant attempt to reinvent the minivan by emphasizing its horizontal proportions and flattening the roof, the Flex and its Lincoln sibling, arrived on the market in 2008, which turned out to be exactly the wrong time; consumers were looking for vehicles with less-exaggeratedly large proportions. Despite Ford's blossoming, the Flex found itself trailing the more conventional Chevy Traverse and Toyota Highlander in the showroom. Ford was expecting to sell 100,000 annually but has struggled to sell a third that many. So far in 2011, only about 2,000 Flexes are finding buyers each month.
Smart Fortwo
Smart is still trying to prove that a funny-looking two-seat car that is challenged at highway speeds and gets mediocre gas mileage will appeal to enough American buyers to constitute a business. Superdealer Roger Penske threw in the towel in February when he returned his exclusive distributor to corporate parent Mercedes-Benz. A new battery-powered version probably isn't going to charge up sales, which fell to 467 in April.
Toyota Tundra
