At the mode selection screen, press Down, Left, Up, Right, X, Y, L, R to unlock a fourth color set. Alternately, successfully complete expert mode.
Buggy
To unlock the Beelzebub Buggy, finish expert mode in first place.
Jet Buggy
Achieve 100% on the level checker when building your car to gain acess to the Jet Buggy.
LE-2001 truck
At the mode selection screen, press Y, X, Right, Left, Right, Left, Down(2), Up(2). Alternately, successfully complete expert mode in first place with the Coyote.
Random weather in time attack mode
At the mode selection screen, press R, X(7), Y(7).
T4 fighter jet
At the mode selection screen, press Left, Right, Down, X(4). Alternately, achieve 100% on the level checker when building your car.
Unlock expert races
To unlock more Expert races, finish Expert mode with the Beelzebub Buggy on the Championship difficulty level.
Unlock schemes
Finish a racing season in Expert mode to unlock a third color scheme for the vehicles.
Additional colors ...