Ever leave your car somewhere, like an airport parking lot etc. and return to find it gone ?
Well, this may help ( still no guarantees ) :

Connect a spare 15 amp ( blue ) fuse across your battery to blow it.
When leaving your car, pop the hood, remove the cover from the box by the battery and replace fuse #5 with the blown one. Keep the good one with you.
This will disable the fuel pump, ain't nobody goin nowhere.