Automotive finishes of various compositions on metal substrates were exposed vertically in a smog chamber to UV and acidic atmospheres. The pollutants were generated from combinations of SO2, NO, propylene, water, and air. Dews of different compositions were generated and collected twice a day. Spot tests were performed by placing drops of (100 microL) of dews on the surfaces of the paints and heating in an air-circulating oven at 90 C for 24 hours. Visual observation, reflection optical microscopy, profilometry, SEM, and EDS were used to examine surface damage. Various degrees of damage occurred depending upon the dew composition and surface properties. In general, the damage areas were in the form of rings with diameters smaller than the original drop. After rinsing and buffing, the damage was still visible. Microscopy and SEM revealed that the rings consisted of numerous small areas of damage and that swelling, pitting, blistering, and cracking had occurred. EDS showed aluminum and sulfur at the damage surface, while the surrounding area did not. Since the base coat contained Al flakes, this suggested that the acidic dew had penetrated through the top coat into the base coat.