LE-2001 Truck
     At  the  Mode  Selection  screen, press Y, X, Right, Left, Right,
Left, Down, Down, Up, Up.

T4 Fighter Jet
     At the Mode Selection screen, press Left, Right, Down, X, X, X, X.
    
Additional Colors
     At the Mode Selection screen, press Down, Left, Up, Right, X, Y, L, R.

Random Weather in Time Attack Mode
     At the Mode Selection screen, press R, X, X, X, X, X, X, X, Y, Y,
Y, Y, Y, Y, Y.

Super Expert Mode
     At  the  Mode  Selection  screen, press Left, Left, Right, Right,
Left, Right, X, Y, Y, Y, Y, Y, Y, Y, Y.