sandwich a layer of liquid crystals in the middle of the windscreen and wire this into the burglar alarm so that a stolen car displays the word "stolen" in black letters that fill the screen. This not only makes the car hard to drive, it virtually guarantees that every policeman will flag you down.

The advantage of this over an audible alarm is that it doesn't require as much (any?) energy to maintain, so it won't run your battery down and therefore doesn't need to time out after a minute or so. It also won't annoy your neighbours if it goes off accidentally in the middle of the night. In fact, the only person it inconveniences is the thief.
-- gravelpit, May 16 2001

So, they just smash out the windshield. If they're lucky, no cops will notice the lack of glass until the car is safely stowed away in a chop shop, or wherever it's headed.
-- centauri, May 16 2001


I think this would be a good idea, if it wouldn't drive up the cost of the car too much. A busted-out windshield would still be pretty noticeable. Plus, you could always have an audible alarm that goes off if the windshield is broken after the initial alarm.
-- PotatoStew, May 16 2001


How about a big speaker that, if the alarm goes off and is ignored or disabled abnormally and then the car goes in motion, blurts out at maximum legal volume "STOLEN CAR! STOLEN CAR! STOLEN CAR!" THAT would be effective.
-- globaltourniquet, May 17 2001


Sort-of baked-ish. Some UK police forces use a specially adapted car called a 'Rat-Trap' which they park in areas of high auto-theft. It's fairly easy to steal, but after five minutes or so the engine dies, all the doors lock and an alarm operates.
-- angel, May 17 2001


(how does the car know?)
-- absterge, May 17 2001


Why not just have the car made with a built in immobiliser like ordinary people. There are only 2 ways someone can steal my car: A - Load it on a truck (Your system wouldn't prevent this - they could just cover it with a tarpauline.) or B - Bring with them a complete electronic management system, (having first spent 3 weeks learning how to fit) and then spend 4 hours re-wiring the car. The immobiliser is built into the key - without the key the car is a fancy paperweight. New keys can be cut and programmed with a special key I have kept in a safe place. (My bank!)

For even more security you can even fit a tracking device. (http://www.tracker-network.co.uk from £199) This allows the police to find your car after it has been stolen.
-- CasaLoco, May 17 2001


Actually, the car alarms I've seen (or heard, if you want to be pedantic) go off when a locked car is bumped, rather than when it is actually broken into. Perhaps have the LCD thing wired near the ignition switch in such a way that it only activates when the car is started w/o the key being in the ignition.
-- nick_n_uit, May 17 2001


I own a Die Hard Security Battery. It has a remote control. If you arm the battery, it will start 3 times dying after 5 seconds. After that, all electricity is disconnected inside the battery. Has a long term storage feature, vibration detector, and reserve feature in case you leave the lights on. The only way you can jump start, push start, or key start is by dis-arming the battery first.
-- wireless, May 19 2001


I have to confess, that I am more of a fan of the Robocop anti car theft device. Hook the seat and steering wheel to the mains power supply, and when the car is stolen, a harness comes down trapping the thief in the driver seat. 30,000 volts of electricity are then shot into the offender, leaving you with not only your car, but a ready-made barbecue. Everyone is happy.
-- gaffer, May 19 2001


Take the bus.
-- horripilation, Nov 07 2002


Wanna zap the bastards with electricity? Get a lightning lamp (those with an electrode under a glass sphere). I bought one for $30. Turned out it it even worked from 12 volts power supply. Tested it on a car battery. Miracles! It works! So, I took the thing apart. It's just like tesla coil I made in high school! You wire one end to anything metalic and keep the discharge coil somewhere out of sight (it's no bigger than an egg). Nicest way to implement is to get some thin guitar strings and sew them into the driver's seat. Don't know how much voltage the damn thing gives off, but it is enough to burn holes through your back.

Works like a charm, however does not prevent the break-in (had one just a week ago).

Also, If you put something like that into the car, note the air humidity. The coil discharges into air as time passes. If it rains outside, it'll be about 3 days before your battery goes dead.

I tried wiring the coil to the car itself, hoping it would zap anyone that touches it, but it didn't work. For that the discharge coil has to be outside the electrode (i.e. the car. And it would look mighty suspicious if yours had wires running out to some box on the ground. The burglar would first go for it and the discharger doesn't zap by itself. Also, if you get rain, we're talking dead batteries in the matter of hours.

Anyway, if you got $30 and metal strings lying around, something like that is to think about.
-- BESTenemy, Mar 22 2003


How about airbag suspension, and weld spikes to the frame rails on the car. When you "arm" the car - it drops down, driving the spikes into the ground. Good luck moving it, towing it, etc :)
-- frankie-j, Jun 05 2004



random, halfbakery