Hold L1 + R1 and press X, X, Right, X, X, Down, X, X, Left, X, X, Up at the title screen. Release L1 + R1 and a sound will confirm correct code entry. Choose any boarder at the character selection screen and he or she will be replaced by Mix Master Mike on the course, with the ubers of the character that was originally selected. He has decks on his back and a vinyl board. Repeat the code to disable its effect.