ive mannaged to foil the switches evil habbits
mount the switch on your car so that it is laying flat (on it's side) AND the switch moves horizontally to the cars body.
this works amazingly well...bacuase think about it...
the main G-force you get is gonna be from a nose on or a flat land....the only way the switch can turn off in this setup is if you land sideways hard on the wheels...
and all cars have a tenancy for the diff to stabilise it in hte air...so ive noticed that you rarely land on your side hard off a jump...
ive never had a switch turn off on me ever from doing this