The Mach 1 performance package was released in 1969 on the first-generation Mustang. Here we have a 2nd generation Mustang, launched in 1971, sometimes integrated into the first generation, but whose body nevertheless deeply changed. This Mach 1 is so successful that the GT trim level was abandoned. In 1971, this version accounted for a quarter of the 150,000 Mustangs produced.