[Badeye]

There are GPS trackers available for you to purchase that will give you the option. Private Investigators use them all the time for domestic investigations.

[Still Thinking]

Zactly the type of thing I was thinking of if. And if you pay in cash for the device and a couple years in advance for the service, no one can use it against you.

I realize I probably sound paranoid, but I haven't gone out and bought anything to track my car. It's just that it seems like our privacy and our personal control over our lives is being relentlessly chipped away, and I feel like we should be alert to stop as many of those encroachments as we can in advance, and look for ways to keep as much control as we can to ourselves, as a principle, and defy and foil those who would do the chipping.