 The Ford Mustang I was a small, mid-engined (4-cylinder), open two-seater with aluminum body work, that began life as a design exercise and eventually became the progenitor of the famed Ford Mustang.Although it shared few design elements with the final production vehicle, it did lend its name to the line.The Ford Mustang II is a small, front-engined (V8), open "two-plus-two" concept car built by the Ford Motor Company in 1963.