In 1932, DKW merged with Audi, Horch and Wanderer, to form the Auto Union. Auto Union came under Daimler-Benz ownership in 1957, and was finally purchased by the Volkswagen Group in 1964. The last DKW car was the F102 which ceased production in 1966; after this the brand was phased out.
They also produced a less well-known series of rear-wheel drive cars called Schwebeklasse and Sonderklasse with V4 two-stroke engines. Displacement of this engine was 1000cc, later 1100cc. These engines had two extra cylinders for forced induction, so they really appeared like V6es but without sparkplugs on the front cylinder pair.
In 1939, they made a prototype with the first three-cylinder engine. The engine had a displacement of 900 cc and produced 30 hp. With a streamlined body, the car could run at 115 km/h (72 mph). This prototype was to be put into production only after World War II, first as an IFA F9 (later to become Wartburg) in Zschopau, East Germany, and shortly afterwards in DKW-form from Düsseldorf as the 3=6 or F91.
As the Auto Union company originally was situated in Saxony in what became the German Democratic Republic, it took some time for it to regroup after the war ended. The company was registered again in West Germany as Auto Union GmbH in 1949, first as a spare-part provider, but soon to take up production of the RT 125 motorcycle and a newly developed delivery van, called a Schnellaster F800. Their first line of production took place in Düsseldorf. This van used the same engine as the last F8 made before the war.
Their first passenger car was the F89 using the body from the prototype F9 made before the war and the 2 cylinder two-stroke engine from the last F8. Production went on until it had been replaced by the successful 3 cylinder engine which came with the F91. The F91 was in production from 1953 to 1955, and was replaced by the somewhat larger F93 in 1956. The F91 and F93 models all had 900 cc 3-cylinder two-stroke engines, the first ones delivering 34 hp, and the last ones 38 hp. The ignition system of these engines comprised three independent sets of points and coils, one for each cylinder, with the points mounted in a cluster around a single lobed cam at the front end of the crank shaft. The cooling system was of the free convection type assisted by a fan driven from a pulley mounted at the front end of the crank shaft.
The F93 was produced until 1959, and was in turn replaced by the AU1000. These models where produced with a 1000 cc two-stroke engine, with a choice between 44 or 50 hp S versions until 1963. During this transition, production was also moved from Düsseldorf to Ingolstadt where Audi still have their production. From 1957, these cars could be fitted with an optional saxomat, an automatic clutch and, at the time it was the only small car offering this feature. The last versions of the AU1000S also had disk brakes as option, an early development for this technology. A sporting 2+2 seater version was also available as the AU1000 Sp from 1957 to 1964, the first years only as a coupé and from 1962 also as a convertible.
In 1956, the very rare DKW Monza was put into small scale production on a private initiative. This was a sporting, two-seater body made of glassfiber mounted on a standard F93 frame. The car was first called Solitude, but got its final name from the several long distance speed records it made on the Monza racing track in Italy in November 1956. Running in FIA class G, it set several new records, among them 48 hours with average speed 140.961 km/h, 10,000 km with average speed 139.453 km/h and 72 hours with average speed 139.459 km/h. The car was first produced by Dannenhauer & Stauss in Stuttgart, then by Massholder in Heidelberg and at last by Robert Schenk in Stuttgart. The total number of produced cars is said to be around 230 and production was rounded up by the end of 1958.
A more successful range of passenger cars was sold from 1959. This was the Junior/F12 series based on a modern concept from the late 1950s. This range consist of Junior (basic model) made from 1959 to 1961, Junior de Luxe (a little enhanced) from 1961 to 1963, F11 (a little larger) and F12 (larger and bigger engine) from 1963 to 1965 and F12 Roadster from 1964 to 1965. The Junior/F12 series became quite popular, and many cars were produced. An Assembly plant was licenced in Ireland between 1952 to c.1964 and roughly 4,000 DKW vehicles were assembled ranging from saloons, vans, motorbikes to Commercial Combine Harvesters. This was the only DKW factory outside of Germany in Europe.
All the 3-cylinder two-stroke post-war cars had some sporting potential and formed the basis for many rally victories in the 1950s and beginning of 1960s. This made DKW the most winning car brand in the European rally league for several years during the fifties.
In 1960 DKW developed a V6 engine by combining two three cylinder two-stroke engines giving a single V6 engine with a capacity of 1000 cc. Over time the capacity was increased and the final V6 in 1966 had a capacity of 1300 cc. The 1300 cc version developed 83 HP at 5000 rpm using the standard configuration with two carburettors. A four carburettor version produced 100 HP and a six carburettor version produced 130hp. The engine was very light and weighed only 84 kg. The V6 was planned to be used in the Munga and the F102. About 100 V6 engines were built for testing purposes and 13 DKW F102 as well as some Mungas were fitted with the V6 engine in the 1960s.
The last DKW was the F102 coming into production in 1964 as a replacement for the somewhat old-looking AU1000. This model was the direct forerunner of the first post-war Audi, the F103. The main difference was that the Audi used a conventional four-stroke engine. The transition to four-stroke engines marked the end of the DKW marque for passenger cars.
Between 1957 and 1967 Vemag built some models of DKW cars in Brazil. The Vemag factory was added to Volkswagen Group in 1967.
From 1949 to 1962, DKW produced a van with a trailing-arm rear suspension system which incorporated springs in the cross bar assembly. Spanish subsidiary IMOSA also produced a modern successor, introduced in 1963 and called the DKW F 1000 L. This van started with the three cylinder 1000 cc engine, but later received a Mercedes-Benz Diesel engine and finally was renamed a Mercedes-Benz in 1975.
The motorcycle branch of the company produced very famous models such as the RT 125 pre- and post World War II. As reparations after the war, the design drawings of the RT125 were given to Harley-Davidson in the US and BSA in the UK. The HD version was known as the Hummer, while BSA used them for the Bantam. IFA and later MZ models continued in production until the 1990s, when economics finally brought production of the two stroke to an end. Other manufacturers also copied the DKW design, officially or otherwise. This can be seen in the similarity of many small two stroke motorcycles from the 1950s, including a product of Yamaha, Voskhod and Polish WSK.