My MIL just got a 2002 Rendezvous and the alarm just goes off when she shuts the car off. It doesn't just happen once either. It will stop and then it will start again five minutes later. Sometimes it happens 3 times in a row! It is like the car is possessed. At first it would only happen once in a while but now it happens every time the car shuts off. The last few times her husband just disconnected the battery to get it to stop. Any ideas what it could be? Anyone else had this problem? We took to an alarm installation place and they said they couldn't do anything. We took to a dealer and they said they fixed it but the alarm starting going off while she was still there and they wouldn't even give her the $90 she just paid them to fix it!