 The body style was continued through 1960.As Lee Iacocca's assistant general manager and chief engineer, Donald N. Frey, was the head engineer for the Mustang project — supervising the development of the Mustang in a record 18 months — while Iacocca championed the project as Ford Division general manager.The Mustang prototype had been a two-seat, mid-mounted engine roadster, later remodeled as a four-seat car styled under the direction of Project Design Chief Joe Oros and his team of L. David Ash, Gale Halderman, and John Foster in Ford's Lincoln–Mercury Division design studios, which produced the winning design in an intramural design contest instigated by Iacocca.