Purple rain
When you are at the main menu, press Left, Right, Left, Right, Up, Down, Up, Down, Up, Down, Circle(3x's).

Every track in arcade mode
When you are at the main menu, press Left, Right, Left, Right, Up, Down, Up, Down, Triangle(2x's), X.

Cow
When you are at the main menu, press Left, Right, Left, Right, Up, Down, Up, Down, Up, Down, Up, Down, Circle(3x's).

Six cars in two-player mode races
When you are at the main menu, press Left, Right, Left, Right, Up, Down, Up, Down, Square(2x's), X.

Win race
When you are at the main menu, press Left, Right, Left, Right, Up, Down, Up, Down, Square, Triangle, Circle. Then, press L3 in a race to win instantly.