2004 Buick Rendezvous Owner's Manual - Page 272

Integrated Windshield Antenna The antenna in your vehicle is a very thin, metal layer in the windshield. If you look near the edges of the windshield, you can see the outline of the antenna. The connector is at the top of the windshield, where the headliner ends. If you experience difficulty with remote transmitters, such as a garage door opener, try pointing the device through the very top of the windshield. XM™ Satellite Radio Antenna System (48 Contiguous US States) Your XM™ Satellite Radio antenna is located on the roof of your vehicle. Keep this antenna clear of snow and ice build up for clear radio reception. The performance of your XM™ system may be affected if your sunroof is open. Loading items onto the roof of your vehicle can interfere with the performance of your XM™ system. Make sure that the XM™ satellite antenna is not obstructed. 3-132