Anyone who has had the displeasure of finding their ride reduced to a vacant car park and wanted to make sure it wasn't happening again, but didn't have $500 for a remote immobiliser and alarm - I've got a low tech kill switch that will stop anyone from driving off to anywhere with your property again...(it should be noted that this immobiliser is designed for single coil pack ignition systems)
You will need a roll of black insulated electrical wire, a packet of crimp on ring/eyelet terminals, a soldering iron, a small toggle or push on/push off switch (the rating is irrelevant as this switch will not be bearing any current or voltage) and a roll of black electrical tape. Crimp on a ring/eyelet terminal onto one end of the wire and attach the ring/eyelet terminal to the negative terminal on the ignition coil . Run the wire with the rest of the ignition wiring loom back into the cabin and figure out where's a suitable location to conceal your 'kill' switch in the cabin.
Solder the wire you have laid from the coil to one terminal on the switch and then cut off another small length of wire and solder that to the other terminal on the switch to complete the switch as a circuit. Crimp one more eyelet to the short wire from the switch and screw it to a good point under the dash as an earth. Wind the electrical tape around the wire you ran with the existing factory wiring loom in the engine bay to conceal it. Secure the rest of the under dash wiring to prevent it from dropping out or making itself obvious and you're done. When the switch is activated it grounds out the ignition coil, preventing it from creating a spark and firing the engine. The engine will still turn over but won't start and it won't matter how many bypass wires are run, it will not start until the switch is deactivated. It works so well it will even stop you when you've forgotten that you've activated it! A rock solid engine immobilser for a few bucks and a half hour of your time (maybe more if you've stopped for beer o'clock)