In Driver: San Francisco for the PC, PS3, Xbox 360, and Wii, you can unlock the 1983 DeLorean DMC-12 (aka, the Back to the Future car).
To unlock the DeLorean, you just need to complete the Sprint Activity 1.
Once you unlock and purchase the DeLorean, drive it 88 miles per hour to unlock a bonus challenge in the Garage called “Blast from the Past”, which includes a 1971 Pontiac LeMans.