[Excaliber]

Hmmm..... All manufacturers of DOT approved cars have a "roll over" switch for the fuel pump. A rather simple device that when turned upside down disconnects the wires.

Not sure about an "impact" switch however! Like activates the air bag. Such a switch would be tricky to build as a "mechanical" only typed device. Complex enough doing it electronically, what with all the "safeties" one has to incorporate.

Ernie