In the first years after WW II, Detroit was busy retooling from wartime production back to civilian autos for all those returning veterans moving to the new suburbs being created from the G.I. Bill. For the first few post-war years, the cars were basically the same models as they were producing pre-war with a few cosmetic modifications.
1949 would introduce to America's pavement many of the first all new designs with the wider bodies on a lower profile. It was 1949 that introduced the Ford Custom Coupe, the Mercurys that were favored by the low riding customizers of the 50's, and perhaps the best looking of them all, the Buick Roadmaster. These would become the iconic vehicles of the film noir era.
The Roadmaster was long, wide, and would introduce Buick's trademark "holes" in the front fenders that were originally meant to be functional vents for engine heat. More likely the port holes were pretty much a product of the chief designer's admiration for the exhaust ports of WW II fighter planes. The windshield would feature curved glass that enhanced the smoother lines of the new Buicks, and the long hood not only fit the fantasy of the P-51 on wheels, it would also confortably fit the large and long inline 8 powerplants.
The bodies were all new, but the Straight 8 was a holdover from the prewar years, the 320 cubic inch (5.2L) "Fireball Eight". Long and heavy, it was nonetheless very smooth with a sultry low exhaust note. It was rated at 150 bhp which doesn't seem like much for a car almost 18 feet long and over 2 tons, but it produced a hefty torque of 280 foot pounds. For those who loved the luxury of the car doing the shifting the gears, the Dynaflow automatic transmission was standard equipment in all the Roadmasters for 1949.
The Buick Roadmaster was a such a beauty that it shared the big screen with Tom Cruise and Dustin Hoffman in Rain Man, the car being a focal point in Charlie and Raymond's relationship with their late father and their transportation from Cincinnati to Los Angeles.