Roadkill Cheats

You can get all the gang cars in a level and some other cool cars if
you do the side missions

Find a short hill, then hold Down and jump it.

Get unlimited ammo -
First pause the game and select the map page then put in Y,X,X,B,Y,X,X,B. a engine rewing will indaicat correct code entry.
Get max health -
First pause the game and select the map page then put in x,b,x,b,x,b,x,b. A engine reving will indicate correct code entry.
Get more money -
First pause the game and select the map page then put in y,b,y,b,x,a,x,a,down,up.

Press Start to pause game play and highlight the 'Map' option. Then, press Y, A(2), Y, X, B(2), X, A, X, B, Y. The sound of an engine will confirm correct code entry. You still need to find where the original weapon power-up appears, then collect it again. It will also cause some weapons which you have not unlocked to appear next to your garage. However, not all weapon power-ups are next to your garage. They are usually nearby, but on a ledge or around the block.

Pause the game and enter any one of these codes at the map screen:

All guns: Y, A, A, Y, X, B, B, X, A, X, B, Y
Decrease Riot Level: Y, B, A, X, Y, B, A, X, DOWN
Increase Riot Level: Y, B, A, X, Y, B, A, X, UP
Infinite Ammo: Y, X, X, B, Y, X, X, B
Money Cheat: Y, B, Y, B, X, A, X, A, DOWN, UP
Restore Health: X, B, X, B, X, B, X, B
Tornado: Y, B, A, X, X, A, B, Y

Pause the game and enter any one of these codes at the map screen:
All guns: Y, A, A, Y, X, B, B, X, A, X, B, Y
Decrease Riot Level: Y, B, A, X, Y, B, A, X, DOWN
Increase Riot Level: Y, B, A, X, Y, B, A, X, UP
Infinite Ammo: Y, X, X, B, Y, X, X, B
Money Cheat: Y, B, Y, B, X, A, X, A, DOWN, UP
Restore Health: X, B, X, B, X, B, X, B
Tornado: Y, B, A, X, X, A, B, Y