Why does road salt damage cars?

Why does road salt damage cars?
Two normally used chemicals on the highways during winter for ice removal are potassium chloride and sodium chloride. These chemicals are corrosive and cause oxidation on the surfaces of vehicles. Bare metal has nothing to protect it and it will usually rust, as does any unpainted or coated surface on cars. Painted surfaces that do not have a clear coat on them could and will oxidize as well, hence the need for waxing a clean car. Clear coats will eventually get damaged as well but it takes a much longer time.