"...the most prevalent car crime now is house burglary to obtain car keys, without which even the most dedicated thieves struggle to start their intended loot. This lends itself to a degree of confidence in the efficacy of new security technology, wouldn't you say?"

I suppose so... although it sounds like the technology of home security systems needs some beefing up! :-)

Of course, some car thieves work around the new technology by using the old-fashioned method of car-jacking -- stealing a car that is already running. To be honest, I'd rather lose my car to a thief who is stealing it when I'm not in it!!!

Anyway, thanks, Don, for the info about after-market BTI's. I agree with Steve Shaw that the additional expense of building a BTI into a new car as standard equipment -- and repairing the BTI when a thief tries to remove it or when some on-board computer problem arises -- would be an unnecessary burden on law-abiding citizens. We can only hope that auto insurance companies would compensate for this by giving a discount to owners of cars equipped with BTI's.