features as all-steel passenger compartment tops (GM's Turret Top design), improved front suspension, improved hydraulic safety braking system, alloy engine pistons and an improved engine cooling system. In 1938, the wheelbase was stretched 2 inches from 138 to , and the Limited, along with Roadmaster, lost its wooden structural members for steel, making them the last Buick passenger cars to rely upon wood components. In 1939, Buick products underwent a substantial redesign; however, the Limited's "limited" production merited it to continue using its 1938 body. The 1939 Limited offered a sectioned rear compartment separating the driver from the rear passengers, and a glass partition could be raised to provide privacy. AM radios were first offered as an option. Behind the scenes, Cadillac executives lobbied to get the Limited out of production because it infringed on their market. While it was priced in the lower end of its Fleetwood series price point, the Limited was listed at US$2,453 ($ in dollars ) almost equaled Cadillac's factory built Imperial Touring Limousine, which cost almost four times as much as the Buick, in its appointments. Buick executives asserted that Limited production averaged only 1,561 vehicles per year for model years 1938 through 1940, an insignificant amount compared to Cadillac's production of its senior cars. For 1940 Buick renamed some of its Series designations and gave names instead. Buick's Series 40 was named the Special, the Series 50 became the Super, the Series 60 was named the Century, the Series 70 was named the Roadmaster, and the Limited was given both the Series 80 and Series 90, with the Series 90 given to a limousine with a wheelbase and 8-passenger capacity. The engine was a Buick Straight-8 engine, improving to by 1939. Limiteds were the most expensive Buicks in production, riding on the company's longest wheelbase of , and the best appointed cars that Buick built. All Limiteds were built at the Buick factory in Flint, Michigan, while all Cadillacs were built in Detroit at the Clark Street Facility while coachwork was provided by Fisher Body. Production of the Limited, and all Buick continued until the eve of World War II when the last Buick was built February 2, 1942. Following World War II, Buick dropped its extended wheelbase models, and cancelled the Series 90 Limited nameplate. The name Limited was truly appropriate to the cars themselves which were limited to touring sedans and