Some scumbag has put a hole in my drivers door and stolen the car stereo. The lock on that door no longer work, am I ring in thinking if I leave the bar disconnected from the lock they can't get in via the hole they have made again? I haven't had time to strip it all yet and take a look, if I take it apart and repair it is there anything I can to stop them doing it again?

If they have made a hold in the door it's to access what's going on behind the lock so disconnecting it will do little to solve the problem you need to patch the hole