1998 Buick Century Owner's Manual - Page 310

Cleaning Glass Surfaces Glass should be cleaned often. GM Glass Cleaner(GM P r No. 1050427) or a liquid household glass cleaner at will remove normal tobacco smoke and dust filmson interior glass. Don't use abrasive cleaners on glass, because they may cause scratches. Avoid placing decalson 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. Grime from the windshield will stick to the wiper blades and affect their performance. Clean the blade by wiping vigorously with a cloth soaked in full-strength windshield washer solvent. Then rinse the blade with water. Check the wiper blades and clean them as necessary; replace blades that look worn. Weatherstrips Silicone greaseon weatherstrips will make them last longer, seal better, and not stick or squeak. Apply silicone greasewith a clean cloth atleast every six months. During very cold, dampweather more frequent application may be required. (See "Recommended Fluids and Lubricants"in the Index.) Cleaning the Outside the of Windshield and Wiper Blades If the windshield is not clear after using the windshield washer, or if the wiper blade chatters when running, wax, sap or other material maybe on the blade or windshield. Clean the outsideof the windshield with GM Windshield Cleaner, Bon Ami@Powder (non-scratching glass cleaning powder),GM Part No. 1050011. The windshield is clean if beads do not form when you rinse it with water. 6-50