Been looking all over the place for something that would point me in the right direction on this and not sure if I would have to go Full Arduino as the solution but this is what I am attempting to do.
For those not in the know, automobiles that have a high visibility to thieves, owners install a kill switch that sit in between the ignition system and the starting system, usually this is just a simple on/off mechanical toggle switch. Nowadays what I am proposing is handled through key fobs, proximity sensors and the like. This would be bit added security for older cars, think 2011 and older.
I am wanting to implement a switch style that is found on higher end refillable Vapes.
Click button 3 times it locks the switch
Click button 3 more times the switch unlocks
Becomes a momentary witch that would be held down while starting the car, then released.
I just can't figure out if there is something that is already out there or if some type of build would have to be done.
Thanks ahead for in points or resolutions in the right direction.
Back in the 1990s the kind of system you describe was quite common and available as an aftermarket option. It would typically require the driver to enter a PIN before the vehicle would start. Some insurance companies required such an interrupter to be installed. I'm sure you could still find these devices although more user friendly alternatives became standard on virtually all cars through the 1990s and early 2000s.
On my car I simply opened the power line to the ignition coil resistor. That resistor was bypassed to give a hotter spark when starting then when the engine started it was placed in series with the coil. Opening that would allow the car to start and then it would quit as soon as the key was released. I later added a 60 second timer so they could start moving then have a stalled car in traffic. No clue as to what you have in mind but this worked for me.