To make life easier for anyone, I would recommend the 4 post kill swtich, The big posts obvioulsy go in between the pos battery cable, and the smaller ones in between your alternator signal wire (on your alt connector there should be a signal wire going to your ecu) you simply kill that power it kills the car.
The big post and small post are switched separately, so you can kill 2 different things at once.
That's how I hooked mine up, I had a 2 post before and couldn't figure out to kill the car.
Quick question for tech, do we need a Fire Suit for rd3?