[95gto]

Using a relay is the propper way to do it, especially considering the undersized electrical system on these cars. If you use a big enough toggle switch you could just cut the starter wire and extend it to a switch but keep in mind the stater wire in the ignition harness is a 12ga or 10ga wire for a reason. So you would be running thick wires to the switch.

Hooking the kill/immobilizer relay up to the starter solenoid relay under the hood would be more concealed since most thieves would not know what they were looking at. Additionally it would provide an opportunity to do the starter relay wiring upgrade.