Cheat mode:
Unlock any cheat and "Cheat Mode' will appear at the options screen.

Invulnerability:
Get all gold medals in Grand Prix Championship to unlock Invulnerability at the cheat menu.

Runaway:
Get all gold medals in Crash mode to unlock Runaway at the cheat menu.

Drivers Ed car:
Get all gold medals in Driving 101.

1997 Eclipse and 2001 Focus SVT:
Beat Custom Championship twice.

Two player Pursuit mode:
Beat Pursuit 3.

Thanks to Revolution readers Jessie Thornsen and Macdaddyz!