Enter these codes while playing for their effect:
Y, B, A, X, X, A, B, Y-Big heads
Up, Right, Down, Left, Z, Left, Right, Left-Invisibility
Up, Up, Down, Down, A, X, Y, B-Low rider
Up, Up, Left, Left, R, Z, L, Z-Low view
L, L, Left, Right, Z, Z, Z, Z-Monster truck
L, Z, R, Z, Left, Left, Up, Up-Psychedelic view
Up, A, Down, Y, Left, X, Right, B-Strange Car
Up, Up, Right, Right, R, Z, L, Z-Trike cam

Enter the code VADKRAM as a name to unlock all bonuses.