The 1967 Shelby GT500 Super Snake, the 1967 Shelby GT500, the 1965 Shelby GT350R, the 1969 Boss 429 and the 1965 Shelby GT350 Supercharged are some of the rarest Ford Mustangs. Some models had limited production runs, and others are one-of-a-kind factory-produced models.
Only 849 Boss 429s were built by Ford, which originally produced it to get the Mustang accepted by NASCAR, making it very rare and popular with racing enthusiasts. The 1967 GT500 was a limited-production run also, and had its popularity skyrocket when the model starred as Eleanor in the hit movie "Gone in 60 Seconds." The 1965 GT350R models are among the rarest, with only 34 made. The Super Snake and the GT350 Supercharged are the rarest of all, with only one of each manufactured.