Gps.......?

i have a extra gps tracking devise. it says legent and garmin on it. it locates way points and stuff like that. i was wondering if you could put it on someones car and track were they're going without you there and without them knowing. can anyone give me specific instructions on how to do this??

Nope. The Garmin eTrex Legend is a handheld GPS device that will pinpoint your location when you're out trekking or just walking about. It doesn't track your whereabouts.

For that you need a GPS tracking device like the Trackstick or i-gotu GPS data logger.