1996 Pontiac Bonneville Owner's Manual - Page 300

Underbody Maintenance Chemicals usedfor ice and snow removal and dust control can collect on the underbody.If these are not removed, accelerated corrosion (rust) occur on can the underbody parts such as lines, frame,floor fuel pan, and exhaust system even though they have corrosion protection. Chemical Paint Spotting Some weather and atmospheric conditions can create a chemical fallout. Airborne pollutants can fall uponand 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 causes this, Pontiac job will repair, at charge to the owner, the surfaces no of At least every spring,flush these materialsfrom the underbody with plain water. Clean any areas where mud new vehicles damaged by fallout condition within this and other debris can collect. packed in closed areas Dirt 12 months or 12,000 miles (20 000 km) of purchase, of the frame should be loosened before being flushed. whichever occursfirst. Your dealer oran underbody vehicle washing system can do this for you.