For the following, you have to go to the profiles page, create a new profile and
Type in these for the following effects:
TheGoodStuff-Unlock classic cars and some tracks
WheelToWheel-Unlock various cars and tracks
NoHoldingBack OR NoHoldsBarred-Unlimited bonuses
To unlock experts cars, get 12,000 points in the career mode.
To unlock classic cars, get 40,000 point from the career mode.
To unlock unlimited cars, get 40,000 points from the career mode.
To unlock some Hidden Cars, go to the credits screen at the options category and press the following for the following effects:
Ford RS 200 RallyCross-Right, Left, A, Down, Down
Citroen Xsara Kit Car-Left, Left, A, Right, Right
Renault 5 Turbo-Down, Right, A, A, Right
Saab 9-3 Viggen-Up, Down, Down, Right, A
Nissan Micra-Left, Up, Left, A, Left