the "Torpedo" bodied 10 HP Amilcar "Type E", was not too far from the same price band, at only 27,900 francs, even in its newly announced extended wheelbase form. The all-steel body Till 1924 car bodies - even those of mass-produced Citroëns - were made according to methods derived directly from the carriage trade, using a timber-frame. Each piece of the frame was individually shaped, normally from ash or beech wood, using traditional carpenters' tools. Sheets of steel (or, in some cases, of fabric) were attached to the outside of the timber frame to cover and protect both the frame and the interior of the automobile from the weather, but the steel sheets added no significant structural strength to that already provided by the timber frame. In fact the first steel bodied "Type B10" cars were subject to significant flexing and distortion that damaged the company's reputation, but these were overcome through the addition of steel reinforcements: any reputational damage was short-lived, and by 1928 sales of the 10 HP "B-series" Citroën, by now in its "Type B12" incarnation, were higher than ever. In 1923, Citroën returned to United States, where this time he began a business relationship with American engineer Edward Gowen Budd. From 1899, Budd had worked to develop stainless steel bodies for railroad cars, for the Pullman in particular. Budd went on to manufacture steel bodies for many automakers, Dodge being his first big auto client. In Europe the Citroën B10 was the first car to use an "all-steel" ("tout-acier") body. Although individual flat sheets of steel were structurally weak and prone to deform under pressure, once a steel sheet was stamped into a three-dimensional shape it became much more rigid, and by welding a number of these three-dimensional sheets together it became possible to create a car body stronger than a traditional timber framed car body, but one that weighed much less, so that the cars that used all steel bodies could be powered by smaller cheaper engines, or else provide more speed and better fuel economy. "All-steel" car bodies transformed the look, the noise and the smell car factories. They also transformed the economics of making cars. The heavy presses needed to make the steel panels were expensive, which was leading to a situation in Germany whereby many auto-makers would soon be buying their car bodies from one Ambi-Budd factory in Berlin. In France larger