My family had a CB radio in our car. I guess we were lucky that we lived in a low crime area, because as it turns out, CB theft was a problem in some areas and the giant antenna we used was the perfect beacon for would-be thieves. What is the solution when people are stealing stuff from you car? Take the stuff with you!
Here is an article from that talks a little bit about the problem and illustrates a solution to foil those car thieves lurking in the shadows.