Unlimited Turbos
     At the Main Menu, press R2, L1, Square, Triangle, R1, L2, L1, R2.

Small Cars
     At  the  Main Menu, press Square, R2, L2, Triangle, Triangle, L2,
R2, Square.

Large Tires
     At  the  Main Menu, press Square, Triangle, Square, Triangle, R1,
R1, L2, L2.

TowJam Car
     At the Main Menu, press Square, Triangle, L1, R1, L2, R2, Square,
Triangle.

Flat Shaded Graphics
     At the Main Menu, press L1, R1, L2, R2, L1, R1, L2, R2.

Dude Sounds
     At the Main Menu, press R2, R1, L2, R2, Square, Triangle, L1, R1.