1998 GMC Sonoma Owner's Manual - Page 307

Finish Care Occasional waxing or mild polishing of your vehicle by hand may be necessary to remove residue from the paint finish. You can get GM-approved cleaning products from your dealer. (See "Appearance Care and Materials" in the Index.) Your vehicle has a "basecoatlclearcoat"paint finish. The clearcoat gives more depth and gloss to the colored basecoat. Always use waxes and polishes that are non-abrasive and made for a basecoat/clearcoat paint finish. necessary, use non-abrasive cleaners that are marked safe for painted surfaces to remove foreign matter. Exterior painted surfaces are subject to aging, weather and chemical fallout that can take their toll over a period of years. You can help to keep the paint finish looking new by keeping your vehicle garaged or covered whenever possible. Cleaning Aluminum Wheels (If Equipped) Keep your wheels clean using a soft clean cloth with mild soap and water. Rinse with clean water. After rinsing thoroughly, dry with a soft clean towel. A wax may then be applied. The surface of these wheels IS similar to the painted surface of your car. Don't use strong soaps, chemicals, abrasive polishes, abrasive cleaners orabrasive cleaning brushes on them because you could damage the surface. Don't take your vehicle through an automatic car wash that has silicon carbide tire cleaning brushes. These brushes can also damage the surface of these wheels. I NOTICE: Machine compounding or aggressive polishing on a basecoatklearcoat paint finish may dull the finish or leave swirl marks. Foreign materials such as calcium chloride and other salts, ice melting agents, road oil and tar, tree sap, bird droppings, chemicalsfrom industrial chimneys, etc., can damage your vehicle's finish if they remain on painted surfaces. Wash the vehicle as soon as possible. If 6-57