I understand, and don't disagree. It just seems to add a level of complexity that I want to avoid.
I might add that you still have a charge wire running up the inside of your car and while it might not be 1/0 gauge, I bet it is still big enough to catch something on fire in the same situation I am working to avoid. So the Ford solenoid really doesn't fix the issue. Well, except that you can fuse the smaller charge cable much more easily.
As for the Inertia switch I would look at a simple Ford Ranger switch that you could cut power to the electric fuel pump if your running one so in a rear end crash your pump shuts off. If not wire it to kill your ignition to kill the engine.
That is certainly the most common use for an inertia switch. I currently don't have EFI or an electric fuel pump (but it's in the works), killing the motor still doesn't fix the issue of a rather large cable hooked to the battery.
