2001 Buick Regal Owner's Manual - Page 178

On cars equipped with the rear window defogger and built-in antenna, the defogger grid serves as a radio antenna. Do not apply aftermarket glass tinting to the back glass. The metallic film in some tinting materials will interfere with or distort the incoming radio reception. Care must be taken when cleaning the rear window because breaks in the resistive material heating element will adversely affect radio performance and defogger performance. See your dealer for details. NOTICE: Do not try to clear frost or other material from the inside of the rear window with a razor blade or anything else that is sharp. This may damage the rear defogger grid and affect your radio's ability to pick up stations clearly. The repairs wouldn't be covered by your warranty. If, when you turn on your rear window defogger, you hear static on your radio station, it could mean that a defogger grid line has been damaged. If this is true, the grid line must be repaired. If you choose to add an aftermarket cellular telephone to your vehicle, and the antenna needs to be attached to the glass, be sure that you do not damage the grid lines for the AM-FM antennas or place the cellular telephone antenna over the grid lines. Diversity Antenna System (If Equipped) Your AM-FM antennas are located in the front windshield and rear window. Be sure that the inside surfaces of the front windshield and rear window are not scratched and that the lines on the glass are not damaged. If the inside surfaces are damaged, they could interfere with radio reception. Also, for proper radio reception, the antenna connector at the top-center of the front windshield and the antenna connector at the top-center of the rear window need to be properly attached to the posts on the glass. 3-27