GPS vehicle locators
Try to steer away from the kind that plugs into the OBD2 port, and pulls data from the vehicle's ECM. They put them in our company trucks, and the nanny box burnt the ECM up in my company truck in about a month. The area I work in is mountainous and very curvy roads. The GPS tracker thing was pulling so much data at a time from my truck......the ECM committed sideways! GM said they would not warranty the replacement and labor if the tracker was hooked back up. I still haven't stolen the truck because they can't see me....lol. Good luck in your search.