GPS tracker and wire in a hidden kill switch. There are a number of wires on this car that if you cut will render the car inoperable. Find one, cut it, run a hidden switch. Tell no one. Put it somewhere that if you get out of the car you can quickly flip it. Tell no one. Make sure nobody sees you flip it. Don’t wire it into a fog light or defrost switch as the first place I’d check.
GPS tracker as a backup.
remove your door pins. I’ve demonstrated in the past that I can break into a locked Foxbody in about 5 seconds with a thin screwdriver