Fight for your life: 
square,triangle,circle,square,square. You will now fight five cars in the 
arena.

Power-up box:
On the Rooftop level, the is a crane holding a red box. Position yourself on 
the top of one of the buildings (there is one that faces the box at eye-level), 
and shoot the box. It will fall onto the roof below, and when you blow it up, 
there are three powerups in there.

Infinite weapons: 
square, triangle, x, space(right direction key), circle

To get to the last stage(rooftop) put in the password: 
SQUARE, TRIANGLE, X, CIRCLE, X.

Invulnerbility -- Square, Triangle, X, Space(right direction key), Circle

Infinite Weapons -- Triangle, Space(right direction key), Square, Circle, Circle

Fight Minion -- Triangle, X, Circle, Square, Triangle

Unknown -- Triangle, X, Triangle, Triangle, Circle

Warehouse level: Cir, Tri, Sq, Cir, Cir

Freeway level: X, Sq, Sq, Cir, Tri

River Park level: X, Tri, Sq, Cir, Sq

Cyburbia: X, Sq, Tri, Tri, Tri

Rooftop: Sq, Tri, X, Cir, X

Fight for your life (5 in arena): Sq, Tri, Cir, Sq, Sq

Helicopter view: Cir, Cir, Tri, X, Blank (then choose view [Start, Up] 
when racing on Arena or Rooftop only)

Invincibility: Sq, Tri, X, Blank, Cir

Unlimited Weapons: Tri, Blank, Sq, Cir, Cir

Rooftop w/Minion and others: Tri, X, Cir, Sq, Tri 

Weird one: Tri, X, Tri, Tri, Cir

On the Cyburbia stage, drive into the front of the Big J convenience store 
and you'll get power missles. 

MINION:
Go to the password screen and put in this password, S,T,T,space,S.

In the warehouse district in two player there is a huge orange dumpster 
on the side street blow it up and a charging station appears, If you position 
your car just right you can see through walls.