Daughter's 87 iroc Z28 has strange things happening with the rear hatch and battery. Just noticed the other day that the hatch wasn't closed all the way and there was no power pulling it shut so we closed it manually. A couple of days later the battery was dead. Put battery on charger then drove car and had battery and alt. checked. Both were new in August and checked out fine. Here is strange part..while walking around back of car I noticed a slow clunking sound coming from the area near the license plate. Next morning the battery is dead again, the little black box (I think relay or solenoid?? Husband took it off hoping to keep battery from going dead again) is out of the car. So the hatch is closed, that little black thingy is out, battery is dead but I still hear the slow clunking. Any suggestions?