to be honest, I would rather I woke up and found my car gone and the house never entered than wake up to have to deal with tooled up scum willing to do harm to get the keys.

Regardless if they manage to get the car or not, your still left with smashed windows or damaged locks, and the horrible feeling that some dirty scrote has been in your home. If the dont manage to take it you will have the next few months waking at every sound thinking someone is trying to get it again and worse still if you manage to defend your property at the missfortune of the intruder, you have to justify your level of force?

I would be more concerned at the possibility of insurance companies begining to refuse to pay out if your car is taken with keys regardless of how they are obtained, that would be a nightmare!