directional signals, chrome wheel discs, and automatic interior courtesy lights. Standard was the "Super Jetfire" I6 engine and was available with optional dual-range Hydramatic automatic transmission or a Warner Gear overdrive unit. Due to materials restrictions caused by the Korean War, Nash sales, like those of many other carmakers, dropped off sharply in 1952. 1953 The Ambassador received minor changes, such as small chrome spacers on the cowl air scoop. Ambassadors were available with dual carburetors and a high-compression aluminum head produceding as the "Le Mans" option as from the Nash-Healey. With the end of the Korean War, a battle for market leadership began between two historic rival automakers, Ford and Chevrolet. There was also a shift from a seller's to a buyer's market making it more difficult for the smaller U.S. automakers to compete with the Big Three (Ford, GM and Chrysler). The Big Three could afford annual styling changes to enhance their sales appeal. 1954 In 1954 the Nash Ambassador was the first American automobile to have a front-end, fully integrated heating, ventilating, and air-conditioning system. The heating and ventilation system was called Weather Eye and now could be equipped with Nash-Kelvinators' advanced Automobile air conditioning unit. While other manufacturers in America at the time offered A/C on some models, their air conditioning units were driven by a large and heavy, trunk mounted expander and heat exchanger that carried the air into the car via clear plastic tubes and out through ceiling mounted vents. Nash's unit was inexpensive, compact, fit under the hood, and could either circulate fresh or recycled air. With a single thermostatic control, the Nash passenger compartment air cooling option was described as "a good and remarkably inexpensive" system. The option was priced well below systems offered by other carmakers (in 1955, Nash offered it at US$345, against $550 for Oldsmobile or $570 for Chrysler); other makers, such as Ford, did not even offer optional air conditioning. (At the time, even a heater was not always standard equipment.) The Ambassador continued with only a few changes. A new "floating" grille concave grille and partially chromed headlamp bezels were added to the front end. A redesigned instrument panel was a major change inside. The base trim was called "Super" while the higher "Custom" models featured a continental spare tire carrier and many other upgrades were available in four-door sedan and two-door "Country Club" hardtop forms. The