Buy a house that has a garage.
Since moving into this house, this is the second time my car has been vandalized. (The first time was with eggs, which I was able to clean up without any major permanent damage.) My alarm must have gone off and scared them from actually taking anything from the car. As far as I can see, everything is still there. I had gotten lax about leaving the face plate attached to the head unit. That or the radar detector, or maybe my Bible, were the only things of value (besides the car itself) in plain sight. Lesson learned. Tomorrow (since everything is closed today), I find out how costly of a lesson it was.