I usually try to back into a parking spot if I can. I figure they will roll up with a flatbed if they are going to take it. That's what I would do. A kill switch would be a good deterent and is easy enough to rig up. I try to park near some high priced beamers or benzs or vettes. I figure they will take them before they take my pile of parts. Lojack would be ok but they already have your car and by the time you get to it the only thing left will be the transmitter.