1940 Mercury Coupe Sedan. Price when new was $ 978. Powered by 239.4 Flathead V-8 rated at 95 horsepower. Total 1940 Mercury production was 81,128. This is the rarest 1940 body style. Strongly resembles the hardtop convertible body style that would be introduced by GM on its all new post-war 49's, and would become the most popular body style of the nineteen fifties. Mercury's first real pillarless hardtop did not arrive until 1952, some twelve years later.