1996 GMC Sonoma Owner's Manual - Page 281

Sheet Metal Damage If your vehicle is.damaged and requires sheet metal repair or replacement, make sure the body repair shop applies anti-corrosion material to the parts repaired or replaced to restore corrosion protection. At least every spring, flushthese materials from the underbody with plain water. Clean any areas where mud and other debriscan collect. Dirt packed in closed areas of the frame should be loosened before being flushed. Your dealer or an underbody vehicle washing system can do this for you. Finish Damage Any stone chips, fractures or deep scratches the finish in should be repaired right away. Bare metal will corrode quickly and may develop into a major repair expense. Minor chips and scratches can be repaired with touch-up materials available from your dealer or other service outlets. Larger areas of finish damage can be corrected in your dealer's body and paint shop. Chemical Paint Spotting Some weather and atmospheric conditionscan create a chemical fallout. Airborne pollutants can fall upon and attack painted surfaces on your vehicle. This damage can take two forms: blotchy, ringlet-shaped discolorations, and small irregular dark spots etched into the paint surface. Although no defect in the paint job causes this,' GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by this fallout condition within 12 months or 12,000miles (20 000 km) of purchase, whichever occurs first. This applies only to materials manufactured and sold by General Motors. Bodies, body conversions orequipment not made or sold by General Motors are not covered. Underbody Maintenance Chemicals used for ice and snow removal and dust control can collect on the underbody. If these are not removed, accelerated corrosion (rust) can occuron the underbody parts such as fuel lines, frame, floor pan, and exhaust system even though they have corrosion protection.