The 1962 Ford Mustang I concept car had its engine in which position?

The 1962 Ford Mustang I concept car had a mid-engine layout.

Ford placed the Mustang I’s compact V4 engine directly behind the cockpit, making it a mid-engined sports car. The open two-seat prototype was conceived as a nimble, low-cost performance car, with four-wheel independent suspension, rack-and-pinion steering and front disc brakes. Its layout was far more exotic than that of the production Mustang that followed.

The engine was a 1.5-liter Ford Cardinal 60-degree V4 paired with a four-speed transmission in a shared transaxle arrangement. The running prototype had an aluminum body over a space frame, while a separate non-running show mock-up used fiberglass. Ford completed the working car in roughly 100 days, and Dan Gurney demonstrated it at the 1962 United States Grand Prix at Watkins Glen.

A major source of confusion is the later Mustang II concept and the production Mustang. Both used more conventional front-engine layouts; the mid-engine arrangement belonged specifically to the original 1962 Mustang I.