I recently bought a 2000 grand prix gtp and i noticed that when i have been driving for a longer period of time the door locks will unlock themselves automatically and do so every 20 seconds or sooner until i figit with the switch unlocking and locking it a few times(even this doesnt work sometimes). I've heard that remote doorlocks can cause this in some cars as a warning that the battery is low in the remote. so i took the battery out of it and it still does it every so often. May be the switch? relay? Any Ideas?