LE-2001 truck:
Press Y, X, Right, Left, Right, Left, Down, Down, Up, Up at the mode selection
screen. Alternately, successfully complete expert mode in first place using the Coyote.

T4 fighter jet:
Press Left, Right, Down, X(4) at the mode selection screen. Alternately, achieve
100% on the level checker when building your car. 

Additional colors:
Press Down, Left, Up, Right, X, Y, L, R at the mode selection screen to unlock a
fourth color set. Alternately, successfully complete expert mode. 

Random weather in time attack mode:
Press R, X(7), Y(7) at the mode selection screen. 

Super expert mode:
Press Left, Left, Right, Right, Left, Right, X, Y(8) at the mode selection screen.
Alternately, successfully complete expert mode under the championship difficulty using
the Beelzebub Buggy. 

Beelzebub Buggy:
Successfully complete expert mode in first place.