Codes

Start with $1,000,000!
When playing the game, plug a DC Keyboard into Controller Port D. (If you get a message, press Start to keep playing.) Type in ''goldfinger.'' You'll hear a sound effect. Then type in ''givememoneyordie.'' Another sound effect. Press Start to pause, select Quit, and start a new game in Career mode.
Unlock Jeep CJ7
At the start screen push L, R, R, DOWN, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, L, L, L, L, R, UP and you will heard a honk.

Easter Eggs

Hidden Arizona Town
In Arizona, make a 180 at the start and go through checkpoint 6. Keep going straight until you reach an old west town. It also contains a box of money next to the saloon.
Hidden Roads
Salvage Wasteland: Make a 180 at the start. Crash through the gates to find the hidden road.

Truck Stop 101: Go through the stoplights before Checkpoint 9. There's a hidden road up a bit.

Motocross: Right at the start, turn left. Keep going until you drive off a ledge. There's a mountian up ahead with a track surrounding it, much like the one in the race.