Acid rain, road silt and fallout are the enemy of paint. Water and Zymol Clear TM wash away the loose particulates but not the embedded pollution. The sun acts as a catalyst to help these paint-toxic pollutants penetrate and destroy your paint. Lehm-Klay, a Professional natural cleaner and HD Cleanse for automotive paint, is a superior remedy for acid rain etch, moderate abrasions, bird droppings and light oxidation.