The Mercury XM-800 concept car was designed by John Najjar and first exhibited at the 1954 Chicago Auto Show. The design of the XM-800 heavily influenced Lincoln and Mercury's 1955 and 1956 models. The 1955 Mercury used a 119-inch wheelbase body and the Lincoln Capri and Premiere used a 126-inch body. The name 'Montclair' was new for 1955 and possibly comes from a new Jersey Community. Ford's new Y-block V8 was given to the Montclair in 4,778cc (292) for 1955 and 5,115cc (312) for 1956. The Montclair was launched as a 4-door sedan, 2-door hardtop and convertible and in 1956 the 4-door Phaeton hardtop was added. There was briefly a 'Sun Valley' hardtop with plexiglass roof but this proved too hot in the summer and few were sold. Almost one third of all Mercurys sold were the entry level Montclair and the majority of those were the 2-door coupe; 104,000 Montclair were sold in 1955, and 91,000 in 1956.