Battery/Alternator Kill Switch location

As I recall, it has to be on the rear.

I mounted an optima in the trunk, on the passenger side,just aft of the wheelhouse. Right behind it I mounted the kill switch with a remote link-rod, that passes through the rear sheet metal, just below the taillight, and is sealed with a grommet. IMHO, this is about as slick as it gets.On raceday, hang a flag off it. My switch has been on there since about 2004, and still works like new.
You need a 2 circuit switch. The primary, high-current sw kills everything except the alternator. The secondary switch kills that. If you are stuck with a single circuit switch, you can still kill the alternator , but with a hi-current NO-relay, signaled off any battery fed circuit.