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 of the Rouge factory two years later.