One of my favorite systems I saw a while back was a club that attached to the steering wheel. It was unique in that it also had a taser system so if you touched the club you'd get zapped. They don't make them anymore, but they do show up used from time to time. Anything that makes your car less desireable to steal, is usually the best you can do. But like everybody here has said, any system can be defeated, if somebody wants your car enough. In the past a few members here had posted renting RV's and trailers and staying at a campground with your car, where your closer to it, and can here someone messing around, but eve that's not fullproof. Thieves just suck!