Citroën re-equipped his factory as a scaled down version of the Ford River Rouge Plant, that he had visited in Detroit Michigan. It was advertised as "Europe's first mass production car." The Type A reached a production number of 24,093 vehicles. The Opel 4 PS, Germany's first 'peoples car', popularly known as the Opel Laubfrosch (Opel Treefrog), was a small two-seater car introduced by the then family owned auto maker Opel, early in 1924, which bore an uncanny resemblance to the little Torpedo Citroën 5 CV of 1922. On an even smaller scale, European cars, such as the 747 cc Austin Seven, (which made cyclecars obsolete overnight.) The Austin 7 was considerably smaller than the Ford Model T. The wheelbase was only , and the track only . Equally it was lighter - less than half the Ford's weight at . The engine required for adequate performance was therefore equally reduced and the sidevalve was quite capable with a modest output. It would also start to catch on in Japan during the same time period, as a Datsun Type 11 that may have been pirated, at the start of their own automobile industry. It was also produced as a BMW Dixi and BMW 3/15 in Germany, Rosengart in France with French styled bodywork, and by American Austin Car Company with American styling, (later American Bantam) in the U.S. It displaced the motorcycle and sidecar combination that was popular in Europe in the 1920s. It spawned a whole industry of 'specials' builders. Swallow Sidecars switched to making cars based on Austin Seven chassis during the 1920s, then made their own complete cars in the 1930s as SS. With the advent of Nazi Germany the company changed its name to Jaguar. The Seven continued to be produced until the late 1930s along with an updated and restyled closed body, known as the "Big Seven" until World War II, but still on the early 1920s running gear, but with a slightly enlarged chassis and widened track. In the late-1920s, General Motors finally overtook Ford, as the U.S. new car market doubled in size, and fragmented into niches on a wave of prosperity, with GM producing a range of cars to match. This included a Chevrolet economy car that was just an entry level model for the range of cars. It was only a small part of the marketing strategy - "A car for