With the Treaty of Versailles marking the end of World War I the automobile industry in Germany changed its focus from the production of military vehicles back to vehicles for the civilian population. Despite post-war economic problems it was clear the car was here to stay - between 1924 and 1928 the number of cars in Germany grew from 420,000 to 1,200,000. As the car became more popular it became more accessible to more of society. The 1920's marked the first time a car was built and targeted at the 'man in the street'. Key brands in this growth - soon to become a strong alliance - made a major impact on the world: A post-war rethink by Audi's Technical Director Hermann Lange led to a completely new design principle for the 'new Audi'. AUDI was one of few medium sized companies and despite the quality of the cars there simply weren't enough being produced. In 1928 AUDI Werke AG was acquired by JS Rasmussen, the head of the DKW empire. A decision was made that AUDI should develop cars of a simpler design which were cheaper to build and used less ambitious constructional features. Rasmussen gave a brief to designers to build a small car powered by a DKW motorcycle engine, with swing axle suspension, front wheel drive and a wooden body - to be developed in six weeks! Amazingly the brief was completed and the car went on to sell over 250,000 units, making it Germany's most popular car at the time. Throughout this period AUDI was a leading light in the concept of aero-dynamic design and streamlined bodywork. Concepts developed in the 1920's are still valid today.