One hit knock outs:
     Hold L1 + R1 and press X, Circle, Circle, X at the main menu.

High speed mode:
     Hold  L1 + R1 and press Circle, Circle, Triangle, Triangle at the
main menu.

Chicken heads:
     Hold L1 + R1 and press X, Circle, Circle, Square at the main menu.

Toy block cars:
     Hold L1 + R1 press Circle, Circle, Triangle, Square at the main menu.

Disable HUD:
     Hold L1 + R1 and press X, Square, Triangle, Circle at the main menu.

Japanese Crash:
     Hold L1 + R1 and press Square, Circle, Square, Circle at the main
menu.