you know the big trucks, with what can be used as a ramp on the back of them (the trucks are in the docks area and there is one parked round the film studios) Whenever I see one of these trucks and just wanna mess around, i like to run up behind the truck and jump on the top of the ramp! Then basically the truck will drive you around, you can try shooting paserr bys, but soon enought the cops will shoot the truck, the driver will flee and your a sitting duck
but fun, anyhow.