“Leave the battery out of the cell phone”
What about On-star, or those thumb drive GPS trackers you can buy? is there a way to stop “unknown” receivers ?
On-Star can be defeated ,, simply disconnect the antenna or fuse. (the FBI can listen in to your car via On-star without turning on the red “mic-on” light ,, this does not use the GPS portion of the system but rather it’s cellular function) ..
GPS trackers cannot be effectively stopped as they are hard to detect (receive only) and to hinder their operation you would need to interfere with the GPS signal being received and there is probably a law against that.. as the previous post points out they need to be hidden yet receive signal ,, they are often hidden under the plastic bumper covers as that doesn’t block signal ... you could drive a truck with metal bumpers and no simple place to hide a tracker but I can’t say that would be fully effective...