A protective clear coating covers the surface of original equipment cast aluminum wheels. A surface degradation may develop if frequent automatic car wash cleaning wears off the factory applied protective clear coating. This can happen at some automatic car wash facilities that use aggressive brushes to clean whitewalls and tires. Once you damage the protective clear coating, exposure to caustic cleaners and road salt can cause further surface deterioration. Damage to the protective clear coating is corrected by replacing the damaged wheel; refinishing is no longer recommended.