Imperial Crown was available as a sedan, or as a limousine with a retractable division window. 1949 Imperials are very rare as production records show only 50 Imperial sedans and 85 Imperial Crown limousines were built. The retail price for the 1949 Imperial was US$4,664 ($ in dollars ) and US$5,334 ($ in dollars ) for the Imperial Crown limousine. The new custom-built Imperial sedan was based on the Chrysler New Yorker. It shared the same trim, but had a canvas-covered roof and leather and broadcloth Imperial upholstery. These features were installed by Derham, on the all new postwar Chrysler sheetmetal. Early 1949 Imperial Crowns were actually leftover 1948s. The really new models didn't arrive until March 1949. Their styling was sleeker than previous models, yet conservative. Fewer, but heavier bars were used in the cross-hatched grille. The upper and center horizontal pieces wrapped around the front fenders. Rocker panel moldings, rear fender stoneguards, full length lower-window trim, and horizontal chrome strips on the rear fenders, and from the headlights to about halfway across the front doors, were used to decorate the side body. The 1950 Crosley Hot Shot is often given credit for the first production disc brakes but the Chrysler Imperial Crown actually had them first as standard equipment at the beginning of the 1949 model year. The Crosley disc was a Goodyear development, a caliper type with ventilated rotor, originally designed for aircraft applications. Only the Hot Shot featured it. Lack of sufficient research caused enormous reliability problems, especially in regions requiring the use of salt on winter roads, such as sticking and corrosion. Drum brake conversion for Hot Shots was quite popular. The Chrysler 4-wheel disc brake system was more complex and expensive than Crosley's, but far more efficient and reliable. It was built by Auto Specialties Manufacturing Company (Ausco) of St. Joseph, Michigan, under patents of inventor H.L. Lambert, and was first tested on a 1939 Plymouth. Unlike the caliper disc, the Ausco-Lambert utilized twin expanding discs that rubbed against the inner surface of a cast iron brake drum, which doubled as the brake housing. The discs spread apart to create friction against the inner drum surface through the action of standard wheel cylinders. Chrysler discs were "self-energizing," in that some of the braking energy itself contributed to the braking effort. This was accomplished by small balls set into oval holes leading to the brake