I've seen this come up several times. Are you speaking of something installed by LE, or something already on the vehicle? I'm not sure most cars have a GPS system built in. Can you point me to some article or information about this? So far, from what I can tell, GPS is one way, to be used for a nav system. To my mind, it wouldn't be something that transmits or tracks the car's location that you could later retrieve.
As with anything, someone could certainly find a way to disable just about any system. I have no idea if the L family cars even have this type of system to begin with.
Was it ever stated that the cars did in fact have GPS recording in them?