True Crime: Streets of LA Cheats

On the map screen, press R1, L1, UP, RIGHT, LEFT, DOWN, L3, R3, X, SQUARE, CIRCLE, TRIANGLE. You should hear a chime to confirm that you did it correctly. Now, go to a place that will save your game. Then, go to the Mission Select Screen and pick a mission that shows Snoop's head to play as him.

Enter at city map screen

Press select during gameplay to go to the map and enter: Up, Down, Up ,Down, X & Up, Right, Down, Left, Up, X.

Pause the game and press up up up up circle triangle square circle x.
You will hear a machine gun and then nicks or snoop dogs voice if you are playing dogg patrol.

Go to the map and press L1(2), R2(2), L2, X, O, Triangle, Square. If you entered the code correctly, you will hear tires screeching.

For the code to work you have to be in a
destination driving mission. 
After pausing the game pick City map and press Left, Right,
Left, Right, X
Heavier Car
For the code to work you have to be in a
destination driving mission. 
After pausing the game pick City map and press Down, Down, Down,
X.  For this to work you have to be in a car before opening the
city map.