Seriously I have to agree with everyone, you should report it. You can get intouch with local rangers, but i think the best point of call here is the police, at least that way any reports that have been filed can be dealt with. Even if you dont know the exact location, you should have a rough idea yeah?
Can you imagine if your car got stolen, im sure im not the only one on here that has pride in them, this did actually happen to a friend of mine and he was pretty crushed..