The guys who stole my son’s truck couldn’t even figure out it was a diesel. It died about 50 miles from his house after they put gas in it.
They can hook up your BMW to a tow truck and haul it back to their shop. Then they have the choice to either chop it up for parts or to take their time making it start. One good option is to find the same year-make-model in a junk yard and buy the immobilizer unit with a matching key, then just swap the immobilizers.
Where’s the data that professional car thieves don’t look for a kill switch?
As pointed out most all car thieves are not professional or smart.
I had a brand new 1980 Chevy PU stolen. For years after I had kill switches installed.
They might not even haul it away. A friend of mine came out to discover that thieves had stolen the doors, and only the doors, off his 328.
Are you trying to tell us that you trusted your car to mechanics and Valets without telling them about the kill switch? Did you do this as a joke?
I had a Miata with a kill switch that the previous owner had installed about 15 years ago. It was just a little toggle switch on the underside of the dashboard a little past my right knee.
If I remember correctly, it controlled the fuel pump, so you could (sometimes) start the car, but it would only run for a few seconds.
They make more sense on a ragtop convertible, since you tend to leave those unlocked.
After the novelty wore off, I mostly forgot to use it. My car was never stolen, so that plan worked out fine.
In my first car I made a simple kill switch myself. I had to very briefly sound the horn twice before cranking. Thought it won’t appeal to the thieves even if they found out. 
Mostly just forgetting to tell them. Nobody ever mentioned it when returning the car.
Lots of aftermarket alarms have an “ignition kill” feature built into them if the alarm goes off. My old car alarm did this, and in order to turn off the alarm/ignition kill if the fob were to fail was a switch located way up under the dash beneath the steering wheel.
CTRL+ALT+DEL for tractors.
A kill switch came with the 1967 Mini I bought about 1981. The battery was in the boot [trunk] on that model so the cable ran from back to front under the body and was intercepted under the passenger seat to fit it.
My salesdog tried to scare talk me into a LoJack system, his spiel was that my car would be towed, put in a shipping container, and sailed to Russia. I asked if the company would track and rescue the car in Moscow (to wit, I didn’t get the LJ).
The best modern car security system is a manual tranny.
I’m wondering if the OP is thinking of the type of sting operation where law enforcement leaves a nice car unlocked with keys in the ignition in a questionable neighborhood, complete with a kill switch and hidden cameras, plus a team of officers nearby to make the arrest. I would assume that in such a situation the officers would wait for the would-be thieves to actually start the car and attempt to drive away before engaging the kill switch. I think that there is a recent thread on this, asking if anyone caught this way could claim entrapment.
I’ve got a highly modified and restored Mazda RX7. To keep thieves away I’ve installed a removable steering wheel. Would love to see their face when the sit in the driver’s seat and finds there is no place to put their hands.
Easier to just pull the fuel pump relay out when you park the car, takes about 20 seconds. Pop hood, open PDU, pull out relay and leave it in the PDU case, close it and and close hood. Pretty good deterrent and unless you have a lambo, it’ll probably deter the casual thief. Added benefit of not shorting out a wiring harness or the PDU by making your own kill switch/one without a resistor.
Yep, great move. Back when cars had “distributors” and “carburetors”, we would go hiking or camping, and would pop a rotor out and take it with us, or hide nearby.
Bet the neighbors loved that.
Nice. Seems really cumbersome to do given the size in comparison to a teeny little relay… well at least it’d be harder to misplace a distributor or piece of it.
I’ve never had a car stolen, but have had a lot of windows smashed. In a few cases I would have preferred the car stolen and not recovered – a lot cheaper than replacing a window! (I carry high insurance deductibles).
My 2004 car doesn’t lock and I’m not in the mood to spend $400 for a BMW remote. I don’t keep anything visible in the car that might tempt thievery. It has a really nice after-market Kenwood stereo/nav/Bluetooth and the display screen folds into the dash; it seems that thieves no longer pry stereos out of dashes(?)
The crackheads who tossed my unlocked 530i in my driveway scored my navigation and radar detector units, some change, and a nasty toilet seat in a bag; I was taking it to Home Depot to match sizes. They didn’t touch my CDs, I assume they are pre-historic stuff to them.
My BFF has had three Honda Civics stolen over the last 20 years. She got one back, the other two disappeared forever. I’ve read that this class of car is stolen at a far higher rate than luxury cars – though I do know someone whose very expensive Dinan engine components were stolen.
You can buy a signal repeater pretty easily - it uses a receiver to listen to the rf code from the key fob, amplifies and rebroadcasts it. Using one of these devices, the thief can open the car from the fob in the house. Once they have physical access, they can disable other security features and drive the car away.
I’ve seen posts from BMW-owning friends who have a small faraday cage in the house for the car fobs to prevent this - of course, they are now courting home invasion for the keys.