The Ford Mustang GTP, an IMSA racecar run by a collaboration between Zakspeed (the same Zakspeed that would go on to dominate Le Mans with the Viper) and Roush. It was powered by a 2.1L turbocharged inline four modified from the 2.3L Lima engine used in the roadgoing Mustangs of the time, and oddly for a top-class prototype it was front engined, giving it an elongated appearance. Unfortunately it had major reliability and cabin heat issues, so it only ran for about two seasons (part of '83 and all of '84) with a total of 3 cars built. The two teams also split up after the Mustang GTP was shelved, and both came back with their own separate Ford-based prototypes later on.