No Clipping Mode

At the main menu type clipped and press [Enter]

Reckless Mode

At the main menu type reckless and press [Enter]

Set # of Laps

At the track selection screen type lapset and press [Enter]

Unknown

At the track selection screen type comeplay and press [Enter]

Pepsi Planet and Cloverleaf Tracks

At the track selection screen type freeride and press [Enter]

Many Tracks

At the track selection screen type freedrive and press [Enter]

Hard Mode

At the car selection screen type takemeon and press [Enter]

Get Xwave Car

At the car selection screen type widebodyopen and press [Enter]

Wraith Car??

At the car selection screen type wildoneopen and press [Enter]

Get Jeff Gordon's Car (at sponsor select)

At the car selection screen type redfury and press [Enter]

Get Wraith Car

At the car selection screen type wildone and press [Enter]