All Arcade Mode Tracks:
Go to the main menu and press Left, Right, Left, Right, Up, Down, Up, Down, Triangle, Triangle, X

All Six Cars for 2 Player races:
Go to the main menu and press Left, Right, Left, Right, Up, Down, Up, Down, Square, Square, X.

Get Cow:
Go to the main menu and press Left, Right, Left, Right, Up, Down, Up, Down, Up, Down, Up, Down, Circle, Circle, Circle

Get Purple Rain:
Go to the main menu and press Left, Right, Left, Right, Up, Down, Up, Down, Up, Down, Circle, Circle, Circle

Get Wire Frame Mode:
Go to the main menu and press Left, Right, Left, Right, Up, Down, Up, Down, Circle, Circle, X.

Easy Win:
Go to the main menu and press Left, Right, Left, Right, Up, Down, Up, Down, Square, Triangle, Circle. During gameplay press L3 to win