To get the secret cars in Twisted Metal 2, go to theCar Selection screen and enter the following codes.You'll hear an explosion if you entered the code correctly:
Minion : L1, Up, Down, Left.
Minion Attack : Up, Down, Up, Up, R2
Sweet Tooth : Up, L1, Triangle, Right.
These moves are executed in-game just like the special moves in beat'em-ups.
Napalm - Right, Left, Up.
Rear Attack - Left, Right, Down.
Jump- Up, Up, Left
Shield- Up, Up, Right
Mine Attack - Right, Left, Down.
Freeze Blast - Left, Right, Up. Shield - Up, Up, Right
Cloaking Attack - Right, Down, Left, Up.Jump - Up, Up, Left.
Rear Freeze - Left,Right,Down,Left,Right,Up.
Also...When playing push Down, Up, Right, Left, Up, Up, Down, Down. This is known as 'buying your soul'(sound familiar to any of you?), which basically means that you trade weapons for life. The more life you will receive.