Two-door fastback

By definition, a fastback is any automobile with a long, moderately curving, downward slope to the rear of the roof. This body style relates to an interest in streamlining and aerodynamics and has gone in and out of fashion at various times. Some (Mustangs for one) have grown quite popular. Others have tended to turn customers off. Certain fastbacks are, technically, two-door sedans or pillared coupes. Four-door fastbacks have also been produced. Many of these (such as Buick's late 1970s four-door Century sedan) lacked sales appeal. Fastbacks may or may not have a rear-opening hatch.