1997 Cadillac DeVille Owner's Manual - Page 339

Underbody Maintenance Chemicals used for and snow removal and dust ice control can collect on the underbody.these are If not removed, accelerated corrosion (rust) can occur on the underbody parts such as fuel lines, frame, floor pan and exhaust system even though they have corrosion protection. Chemical Paint Spotting Some weather and atmospheric conditions create can a chemical fallout. Airborne pollutants fall upon can and attack painted surfaces on your vehicle. This damage can take two forms: blotchy, ringlet-shaped discolorations, and small irregular spots etched dark into the paint surface. Although no defect in the paint causes this, Cadillac job At least every spring, flush these materialsfrom the of underbody with plain water. Clean any areas where mud will repair, at no charge to the owner, the surfaces and other debris can collect. Dirt packed in closed areas new vehicles damaged by this fallout condition within 12 months or 12,000 miles (20 000 k ) purchase, m of of the frame should be loosened before being flushed. whichever occurs first. Your dealer or an underbodycar washing system can do this for you.