First of all: I'd think to put it a more realistic ssengine (collision, spawn, etc...)because that's a hinge with motor and two fake cylinders. It's fine, but it might be better.
Secondly, you should try to make the softwheel's circles a bit heavier, because they can't manage the car's weight well.
Actually 6/10, because I know you can better it!
This is *"#&.
@guns : You are arguing to your scene, the hand gun. This has the same firing mechanism, the same sliding piston (that is really crappy here)and the same mag lock.