the starter can be interrupted by breaking the black with white stripe or black with yellow stripe 12 awg wire that goes to the starter solenoid. it can be traced from the ignition switch to the clutch safety relay in the engine bay back to the starter
also find the fuel pump relay trace the wires back to under the dash board and wire in a switch preferable on the ground side. not the ecu trigger side. if you want to get fancy you can use stock switches in different locations that no one uses or hide switches in places where people it wont look obvious that your looking for a button
also find the fuel pump relay trace the wires back to under the dash board and wire in a switch preferable on the ground side. not the ecu trigger side. if you want to get fancy you can use stock switches in different locations that no one uses or hide switches in places where people it wont look obvious that your looking for a button