Extra Color:
Press Down, Left, Up, Right, X, Y, L, R. Or beat Expert mode to open up another color scheme.

Beelzebub Buggy:
Beat Expert mode in first place to enable this buggy.

More Expert Races:
Press Left, Left, Right, Right, Left, Right, X, Y (8 times). Or beat Expert mode on Championship using the Beelzebub Buggy to enable more races.

Jet Buggy:
Press Left, Right, Down, X (4 times). Or get 100% level checker when building your car.

LE-2001 Truck:
Press Y, X, Right, Left, Right, Left, Down, Down, Up, Up. Or using Coyote, complete Expert Mode in 1st Place.

Thanks to Revolution readers CheatMaster and alitareen!