When on foot, pressing OPTION-2 + OPTION-1 to get a paint sprayer.
Lock viewpoint - when using the left, right, or back viewpoints with the B button, press Option 2, release the B button, and then release Option 2. This will lock the viewscreen to the position you chose until you press B again.
At option board, choose female with short blond hair and pick green car. With car box highlighted, hold Option 1 and press A. Car should change to an all-black design. Start the game, your vehicle will be invisible on radar and by eye.
At option board, choose Biff (blond surfer dude) and the tan car. With the car highlighted, hold Option 1 and press A. Car should change to a red color with a black top. You now have a super-powered car with rapid-fire and unlimited ammo for all weapons!