Corrosion of automobile bodies is caused by electrochemical action from a hostile environment. Prevention of corrosion is complicated by factors of environment, design, manufacturing, and inherent characteristics of materials. These factors are discussed in some detail, as are the problems generated by new materials such as galvanized steel and zinc rich primers. Various methods of imparting corrosion resistance are considered as well as those finally adopted. Electrocoating appears to approach the ideal protection.