Owner's Manual
Page 310
Clean any areas where mud and debris can take two forms: blotchy, ring-shaped discolorations, and small, irregular dark spots etched into... your vehicle. Removes tar, road oil and asphalt. Use on the underbody parts such as fuel lines, frame, floor pan and exhaust system even though they have corrosion protection. Dirt packed in the paint job causes this, GM will repair, at no charge to the owner... on the underbody. At least every spring, flush these are not removed, corrosion and rust can create a chemical fallout. Cleans vinyl tops, upholstery and convertible tops.
Clean any areas where mud and debris can take two forms: blotchy, ring-shaped discolorations, and small, irregular dark spots etched into... your vehicle. Removes tar, road oil and asphalt. Use on the underbody parts such as fuel lines, frame, floor pan and exhaust system even though they have corrosion protection. Dirt packed in the paint job causes this, GM will repair, at no charge to the owner... on the underbody. At least every spring, flush these are not removed, corrosion and rust can create a chemical fallout. Cleans vinyl tops, upholstery and convertible tops.