I'm sorry it's happened to you but, really, what do you expect people to do?
The scrotes who do this have got it down to a fine art and can have the whole thing done in less than two minutes from start to finish, so they've gone before a call to the police can even be completed, and that's even if people know what's happening and know to call the police.
Most people will hear a noise and may look out of the window to see what's going on, only to see a guy in overalls under a car, so the natural and normal assumption is that it's a mechanic doing legitimate work.