Yeah, another thing about BT GPS Transceivers: they auto shutoff after 5 minutes. But, well, that'd be good enough too, right. When the BT signal on the GPS transceiver goes out, log the position.

Other problems with finding cars are that they're often parked in garages.

Many cars are getting BT installed for various things. If you're going to write the BT disconnect demon, may I suggest the following options as well:

a) record the position on a significant and unreversed degradation of the signal (rssi or lq?) as when someone gets out of a car.
b) events for when a known BT MAC comes into range. This would be very useful when wired to the MAC of the Boss's cellphone. Make a desktop widget too and call it "KittyBell". It woudl probably help you find your car too.