Pillarless Hardtops
The automotive usage of the term "hardtop" is most often applied for a fixed roof body style without a center pillar. They were sometimes called a "hardtop convertible" because they were designed to look like a convertible with the top raised. While some early models retained side window frames and B-pillars, by the 1950s most were "pillarless hardtops", omitting the B-pillar (the roof support behind the front doors) and configuring the window frames, if any, to retract with the glass when lowered. Some hardtops took the convertible look even further, including such details as simulating a convertible-top framework in the interior headliner and shaping the roof to resemble a raised canvas top. By the late-1960s such designs were further emphasized with an optional vinyl cover applied on the steel roof.
A pillarless hardtop is inherently less rigid than a pillared body, requiring extra underbody strength to prevent shake. Production hardtops commonly shared the frame or reinforced body structure of the contemporary convertible model, which was already reinforced to compensate for the lack of a fixed roof. With such a reinforced frame, a hardtop was stronger and stiffer than a convertible, but both weaker and (because of the reinforcements) heavier than a pillared body.
There were a variety of hardtop-like body styles dating back to at least the 1920s. Chrysler Corporation built seven pillarless Town and Country hardtop coupes as concept vehicles in 1946, and even included the body style in its advertising that year. Mass-production of hardtops began with General Motors, which launched two-door, pillarless hardtops in 1949 as the Buick Roadmaster Riviera, Oldsmobile 98 Holiday, and Cadillac Coupe de Ville. They were purportedly inspired by the wife of a Buick executive who always drove convertibles, but never lowered the top. The hardtop became extremely popular in the 1950s, and by 1956 every major U.S. automaker offered hardtop coupés and four-door sedans in a particular model lineup. In 1955, Buick and Oldsmobile introduced the first four-door hardtop sedans. In 1956, the first four-door hardtop station wagon was introduced by Rambler. In 1957, Mercury offered both two- and four-door hardtop wagons, the only marque to ever to do so. The type did not catch on, though, as most buyers considered wagons too boxy to benefit from the sporty look (or expensive enough to begin with). All disappeared from the market after 1964. The Facel Vega Excellence is a notable French example of a four-door hardtop from this period, noted for the huge opening with both doors on one side open and for sagging if all the doors were left open. The doors were designed for locking to the floor and not each other.
Throughout the 1960s the two-door pillarless hardtop was by far the most popular body style in most lines where such a model was offered. Even on family-type vehicles like the Chevrolet Impala, the two-door hardtop regularly outsold four-door sedans. Some car lines (such as the 1957 Cadillac and 1965-69 Corvair) only offered pillarless models with no sedans at all.
The hardtop began to disappear along with convertibles in the mid-1970s, partly out of a concern that U.S. federal safety regulations would be difficult for pillarless models to pass. The ascendancy of monocoque construction also made the pillarless design less practical. Some models adopted modified roof styling, placing the B pillars behind tinted side window glass and painting or molding the outer side of each pillar in black to make them less visible, creating a hardtop look without actually omitting the pillar. Some mid to late 1970s models continued their previous two-door hardtop bodies, but with fixed rear windows or a variety of vinyl roof and opera window treatments. The U.S. industry's last true two-door and four-door hardtops were in the 1978 Chrysler Newport and New Yorker lines.
Since then, no U.S. manufacturer has offered a true hardtop in regular production, although some German manufacturers, including BMW and Mercedes-Benz have offered upscale pillarless hardtops. Renault produced a three-door hardtop between 2001 and 2003 in the form of the Avantime.
In the mid-1970s, Toyota introduced the Toyota Crown as a 2- and 4-door hardtop, and Nissan followed suit with the Nissan Cedric and Nissan Gloria. Subaru introduced a new compact coupe as a genuine two-door hardtop with the Subaru Leone in 1971. The hardtop models were more expensive and luxurious than the sedan versions. In the 1980s, Toyota continued the trend with the Toyota Mark II and the Toyota Chaser, with Nissan introducing its Nissan Laurel, and Mazda introducing the Mazda Luce, all as four-door hardtops. During the early 1990s, almost all Japanese car makers had at least one four-door hardtop in multiple classes, including compact sedans, starting with the Toyota Carina ED, Toyota Corona EXiV, Toyota Sprinter Marino, Nissan Presea, Honda Inspire, Honda Integra, Mitsubishi Emeraude, and Mazda Persona. Even Subaru got into the game with the Subaru Legacy. By the end of the 90s, however, almost all four-door hardtops disappeared, as structural integrity standards continued to increase. The Subaru Legacy remained a "B" pillar hardtop until the introduction of the 2010 model.
British luxury carmaker Bentley (owned by Volkswagen Group) sells two true hardtop coupes, the Continental GT fastback, and the Brooklands coupe (2008). Other British pillarless hardtops included the Sunbeam Rapier and the Ford Consul Capri (355) which, unlike American models, sold fewer cars than their saloon cousins. The body style was thought to be making a comeback, as concept versions of the Dodge Challenger and Chevrolet Camaro shown in 2006 were both two-door hardtops, however, the production versions of both included a blacked out B Pillar and fixed rear side glass. Another pillarless design was featured in the 2007 model concept for the Chrysler 300C. The New Mini also included a blacked out B-pillar and fixed rear side glass, although it is labeled 'Hardtop' in the United States.
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