1997 Buick Regal Owner's Manual - Page 193

Backglass Antenna (If Equipped) Your AM-FM antenna is integrated with your rear window defogger, located in the rear window. Be sure that the inside surfaceof the rear window is not scratched and that the lines on the glass are not damaged. If the inside surfaceis damaged, it could interfere with radio reception. ~- - Because this antenna is built into your rear window, there is a reduced risk of damage causedby car washes and vandals. If you choose to adda cellular telephone to yourvehicle, and the antenna needsto beattached to the glass, be sure that you do not damage the grid lines for AM-FM the antenna. There is enough space betweenthe lines to attach a cellular telephone antenna without interfering with radio reception. - - NOTICE: Do not try to clear frost or other material from the inside of the rear window with a razor blade or anythingelse 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.