Enter at the main menu screen
Fast Game Speed - Press L1, L2, R1, R2, Square, Square
There will be a sound and a screen will appear saying which code was entered correctly..!
At the title screen or while the game is paused, press L2, Square, R1, Circle, R1, L1, Circle, L2, Square, R2, Square, R1 to get a million dollars in career mode.
$25,000 cheat
To get access to $25,000, pause the game, hit L2, Square, R1, Square, R1, L1, Circle, L2, Square, R2, Square, R1.
Normal Mode
Enter the following code at th main menu:
L1 - L2 - R1 - R2 - Circle - Circle
Then everything should go back to normal speed
Slow Motion Mode
At the main menu enter:
L1, L2, R1, R2, square, circle
to activate slow motion mode. This mode makes the game go 50% slower, but the lap time clock still goes at normal speed.
Unlock Secret Vehicles
Enter the following code at the Main Menu....
L1 - L2 - R1 -R2 - L1 - R1
Then you will have access to some trucks with multiple gaming magizine's logos on them.