car alarm touch/pressure sensor?

I'm sorry I do not know exactly how to describe what I'm looking for. I have a friend who is a police officer who has described something to me that he has seen and wants me to find where he can get one, lol. I found this forum, and it seems like this is the best place to come to get an answer. Ok, I think this is what I'm looking for, as described by another site: "Touch Sensors These devices hook up to the starter wire under the dash. An existing part of the vehicle, such as the cruise control button, the high beam lever, the wiper switch or even a radio knob, becomes the trigger for this device. The driver has to touch this "secret switch" in order to start the vehicle." He says the one he's seen was more like a pressure sensor on the floor that you have to push to engage the car in addition to standard procedure like pushing on the brake. This would be helpful if an officer has to leave his car to pursue a subject on foot. So, does anyone know where this can be found, without buying an entire alarm kit? Or maybe how to wire it up with just basic tools? Or has anyone ever even heard of this? Lol, thanks for all replies in advance!

You can definitely do this without an alarm kit. A lot of guys with Wrangler's do this to their Jeeps since security is so bad. Head over to jeepforum.com and search "Ignition Kill Switch" That should give you an idea where to start. Should be pretty basic. Hope this helps.

I made a circuit that does this. You need to touch a piece of metal in the car that only you know about. Once you touch this spot the car will start.

I've never heard of a touch sensor specifically, but tying the starter kill into an existing switch on the car is pretty common. Like you said, you could just use a turn signal, high beams, or rear defroster. I think all the thieves are going to do is just turn on every accessory in the car until it starts.....it might slow them down by five or ten seconds......but whatever, if your customer likes it. Search around for the Omega AU-SI-N. It's a little crudely made, but works well. Has a bank of two relays, as well as a fake alarm LED and a button to turn the system off when leaving the car for service. Also, the AU-SI-N has a slot for a third relay you can add. Then, any incorrect attempt to start the car will cause the horn to honk, alerting the car's owner.

Thanks for all of the advice so far. I'm going to look into the things everybody suggested, especially the Omega AU-SI-N. That sounds like what I'm looking for.

https://www.the12volt.com/relays/page2.asp Look there at "passive starter kill relay with remote turnon lead." The AU-SI-N is simply the same thing, but is prewired and comes with a toggle switch and cheap-looking flashing LED. You could just get two relays, wire them up as shown, and connect the wire listed as "remote turnon lead" to anything in the car that makes a positive pulse.........turn signal, defrost, high beam, power window motor wire...whatever. My co-workers learned from experience not to select the parking light wire, because there's too great a chance you'd forget to turn the parking lights back off after starting the car, then park the car and have the battery go dead. So, you could just wire up those relays like that, and even buy yourself a separate flashing LED to drill into the dash if you want.