Roadkill cheats and cheat codes for Playstation 2

Pause the game play and highlight the "Map" option. Then, press the 
following button cheats. The sound of an engine will confirm, 
if the typed codes are accepted.

More money
Triangle, Circle, Triangle, Circle, Square, X, Square, X, Down, Up. 

More money
Triangle, Circle, Triangle, Circle, Square, X, Square, X, Down, Up. 

Unlock all vehicles
Up, Down, Up, Down, Triangle, X, Triangle, X, Square, Circle, Circle, Square.

Unlock Tornado
Triangle, Circle, X, Square, Square, X, Circle, Triangle. 

Refill health
Square, Circle, Square, Circle, Square, Circle, Square, Circle.

Respawn power-ups:
Triangle, X, X, Triangle, Square, Circle, Circle, Square, X, Square, Circle, 
Triangle.

Lower RIOT level
Triangle, Circle, X, Square, Triangle, Circle, X, Square, Down. 

Higher RIOT level
Triangle, Circle, X, Square, Triangle, Circle, X, Square, Up.