As is so often the case in law, punishments for theft do not prevent the actual thefts very much; however, potential penalties for purchasing stolen items might intimidate a higher class of customer (there is a parallel in the prostitution problem). Any item that can be detached and stolen must be resold, always by cash, and always by disreputable outlets. Since airbags are difficult to reinstall, and because most new cars come with airbags already, they are usually not resold “on the street,” but must be sold to someone who will resell them and install them; so that is where detection and enforcement must begin. Actually, the ingredients of the airbag—gases, electronic sensors, etc.—are probably more valuable than the airbag itself. As for wheels, etc., possession is ownership, and the automobile owner cannot hope to claim otherwise. Registry, tracking devices, and other such “paper trails” are economically infeasible—we would have to have four registration numbers for every wheel or tire on every car, two numbers for headlights, etc. Perhaps some sort of replacement insurance would bring the insurance industry into the problem. Another approach might be to complicate the removal mechanisms (special bolts, special tool needed, etc.) Warnings to the general public about purchasing only from reputable dealers might help, and the threat of dis-licensing to them would make them shy away from the practice. Reputable dealers could throw the packaging into the trunk (as mechanics throw in replaced parts of an engine to prove they actually were replaced) to prove legitimate product purchase.