Master code
Press R1(2), Up, Down, R2(2), Left, Right at the title screen.
Richard Petty
Win all the challenges to unlock Richard Petty.
Bonus options
The following bonuses can be unlocked during game play by doing well and earning points.:
AI Vengeance: AI cars retaliate when hit.
Front Wheel Drive: Car has front wheel drive.
Hardcore Physics: Hardcore realism.
Horn Ball: Press Up to shoot a paintball.
Horn Mortar: Press Up to shoot an explosive mortar.
Insane Racecar: Press Up to jump.
Mini Cars: Smaller cars
Monster Cars: High suspension.
Oh Dear: One car on track replaced by monstrous-sized crew member.
Super Draft: Faster draft speed.
Pit crashing
Go into the pits at the end of pit lane. You can crash into cars, which shows on the tack.
Kenyon Raceway: Leave track
After you pass the start/finish line, instead of turning drive straight for the upper right part of the wall. You then should be able to drive past the parked cars and trailers, and exit the other side back out on the race track.
$10,000
To get an extra $10,000 in career mode, at the main menu press up, down, left, right, z, left, left.