The Mustangs that never were

From late 1961 into mid-1962, Ford designers tried out a wide range of themes for a sporty coupe based on the platform of the new Falcon compact. Each design was given an internal name for the purpose of discussion. One fastback design actually went through at least three different names starting with Avventura before moving on to Avanti and finally Allegro. The fastback design was originally sketched with a hatchback and rear-facing second row seat. While this car never made it to production, a variation of the fastback profile was eventually adopted as the third bodystyle for Mustang.

In 1962, the design team, led by Gene Bordinat, worked on several iterations of another design called Allegro. While the production 1965 Mustang was a very different car in almost every visual detail from Allegro, the design study established the basic proportions that would define most Mustangs for the next five decades. The notchback coupe had the same long-hood, short-deck layout with a compact greenhouse that would roll out two years later.

Early in the gestation of the original Mustang, Ford designers also considered a number of two-seaters. These were seen as a more affordable return to the roots of Thunderbird, which by this time had grown into a much larger four-seater. Aside from some track-oriented Mustangs that had the rear seats removed to save weight, there has never been a strictly two-seat production Mustang.

Although it was probably never seriously considered for production as a Mustang, this hard-top variation of the Mustang 1 concept from 1962 did provide some inspiration for the GT40 MK I that would race at Le Mans and elsewhere beginning in 1964.

As Avventura moved from sketch to physical design model, the hatch was replaced with a trunk and the rear seat was switched to a more conventional forward-facing orientation. Originally shown internally as Avanti, the name was eventually changed to Allegro, likely because Studebaker had introduced its own production Avanti coupe around the same time.

This 1964 clay model of a two-seat Mustang incorporates some of the design cues of the production 1965 car including the side scoops.

After the smashing success of the 1965 Mustang, several Ford execs pushed for a four-door version to increase sales even further.

With the Mustang having already set sales records following its launch in 1964, Ford designers went further with the Mach 2 concept, shifting the V-8 to behind the rear seats as a possible successor to the Shelby Cobra. The idea never went further than a few auto shows.

In the mid-1960s, Ford designers considered at least a couple of different concepts for a Mustang station wagon, comparable to the Chevy Nomad, with at least one running prototype based on a 1966 coupe getting built.

In 1967, Ford designers decided to reprise one of the original Mustang design concepts from 1962 with a new form and repurposed name. Starting with the Avanti/Allegro fastback coupe, the greenhouse was removed and replaced with a low-cut speedster-style windshield, rollbar, flying buttresses on the rear deck and a new rear end. The reworked concept was dubbed Allegro II.

The Mach 1, as it was shown at the 1967 Detroit Auto Show with a face closer to production Mustangs of the time. The low-cut roofline and racing-type fuel cap never made it to production, but the hatchback did eventually arrive on the 1974 Mustang II.

As the first-generation Mustang transitioned from a pony car to a larger and heavier big-block muscle car, the Mach 1 concept was created as a preview of the 1968 model. The original nose of the concept drew inspiration from the 1963 Mustang II concept.

First shown at the 1970 Chicago Auto Show, the Mustang Milano concept foreshadowed a few styling touches of the 1971 Mustang — it's pointed nose and long rear deck — but little else.

More Milano styling cues would show up in the Australian market Ford Falcon.

The 1980 Mustang RSX concept was designed by Ghia as a potential entry into European rallying, based on the Fox-body Mustang but with higher ride height for off-roading.

In 1990, Ford designers considered a number of replacements for the aging third-generation Mustang. After departing from many of the original design cues on the third-generation models, the upcoming fourth-generation would return elements like the galloping pony in the grille. This softer concept, known as "Bruce Jenner" wasn't considered aggressive enough to be a Mustang.

This alternative proposal dubbed, "Rambo," was deemed too extreme for production.

The Mach III provided the first public hints of the fourth-generation Mustang, like the grille pony badge, side scoops and tri-bar taillamps that arrived on the 1994 Mustang.

The 2003 Mustang GT concepts heralded the return of several classic Mustang cues to the generation launched in 2005 that's still in production today.