Battery relocated to trunk, inertia switch?

That is a continuous duty solenoid, and is not what Dion is talking about. What you posted is what I was referring to---it requires current draw to keep it alive if you don't shut it off every single time.

If that thing REALLY is good for 200A it is one HELL of a continous duty solenoid, tho...

No, that is similar to what I am talking about. It kind of looks like a continuous duty solenoid but it only takes a 12v pulse to open or close the relay and doesn't require any power to maintain it's state.

The website says "continuous duty" in the text, but the title is "latching" and the text also says "momontary push button":

Painless Wiring

"Our Remote Master Disconnect with Mechanical Latching Solenoid is ideal for everyday vehicle applications and is a simple and effective anti-theft deterrent. It uses a 100 AMP continuous duty solenoid which is activated by an easy to hide momentary push button. No risk of accidentally draining your battery with this latching solenoid. Kit comes complete with one solenoid, one switch, mounting hardware, wire and connectors."

There are several kits out there that are similar.