Corrosion is still the most frequent cause of deficiencies on cars over 5 years old. Life expectancy can be increased by approximately four years if double-sided galvanised sheet metal is used, if the vehicle is suitably designed to avoid corrosion and if currently available corrosion protection measures are carefully applied. The theories behind the corrosion protection properties of galvanised steel, i.e the barrier effect and cathodic protection are discussed in detail. The paper describes how this protective effect of the zinc coating is obtained in practice, and on which areas of the body and under what kinds of corrosive exposure it is effective. The results of this research have been implemented in the production of the Audi 100/Audi 5000 and the Audi 80. The paper describes the 100% galvanised bodyshells manufactured in volume production of these models, and outlines recycling possibilities.