At the main menu screen, press RIGHT, RIGHT, LEFT, SQUARE, UP, L2, L2, R1

To unlock the Humvee, place first in the first three seasons of Career Mode.

To unlock the incomparable Dodge Durango, finish first in the fourth season of Career Mode in the Speed Division.

Beat the first nine tracks in Single Race Mode to unlock the Pro class of trucks.

To unlock the Dodge T-Rex, finish first in the fourth season of Career Mode in the Power Division.

This may sound ill, but it's actually quite cool. To unlock Rod Hall's Hummer, place first in all of the divisions of Career Mode.

Beat the first twenty-seven tracks in Single Race Mode to unlock the Unlimited class of trucks.

Beat the first thirty-six tracks in Single Race Mode to unlock yourself one of them there monster trucks.