GM seemed to have had this right in the late 80s and early 90s with VATS: my Camaro had a resistor integrated into the key, and if the ECM sensed the wrong resi

GM seemed to have had this right in the late 80s and early 90s with VATS: my Camaro had a resistor integrated into the key, and if the ECM sensed the wrong resistance, it wouldn't start or run the ignition. I think there were a large number of possible values, and it would lock you out for a while if it detected a couple of failed attempts. It also seemed pretty good at preventing theft, and can't possibly be more complicated or expensive than the silly fobs everything comes with.