1996 Buick Park Avenue Owner's Manual - Page 299

Glass Glass should be cleaned often. GM Glass Cleaner (GM Part No. 1050427) or a liquid household glass cleaner will remove normal tobacco smoke and dust films. Don't use abrasive cleaners on glass, because they may cause scratches. Avoid placing decals on the inside rear window, since they may have to be scraped off later. If abrasive cleaners are used on the inside of the rear window, an electric defogger element may be damaged. Any temporary license should not be attached across the defogger grid. Cleaning the Outsideof the Windshield and Wiper Blades If the windshield is not clear after using the windshield washer, or if the wiper blade chatters when running, wax or other material may be on the blade or windshield. Clean the outside of the windshield with GM Windshield Cleaner, Bon-Ami Powder@(GM Part No. 1050011). The windshield is clean if beads do not form when you rinse it with water. Clean the blade by wiping vigorously with a cloth soaked in full-strength windshield washer solvent. Then rinse the blade with water. Wiper blades should be checked on a regular basis and replaced when worn.