1955 Plymouth Belvedere: All Plymouths were treated to a major overhaul for the 1955 model year. This was the first year of Chrysler Stylist Virgil Exner's "Forward Look." The Belvedere returned as top-of-the-line.
For 1956, Plymouth styling evolved from that of the 1955s. Most notable would be the introduction of the first push-button automatic transmission to appear in an American automobile, and a more dramatic rear-end treatment highlighted by a pair of rakish tail-fins. In early 1956, the Fury joined the Belvedere line as a special-edition high-performance model. In 1956, Plymouth added seat belts.
After the Fury was expanded to become Plymouth's top model in 1956, the Belvedere was demoted as the middle priced model after the Plaza and Savoy.
In 1956, Chrysler in a public relations campaign took a Belvedere and had turbine engine fitted instead of the standard gasoline engine, and was driven across the US.
Source: Wikipedia, 2013