A fastback is an automotive styling feature, defined by the rear of the car having a single slope from the roof to the tail.
1935 Stout Scarab
1949 Cadillac Series 62 rear
The marketing term liftback describes a hatchback car body style with a rear cargo door, where the overall roof line and rear cargo door are sloped more like that of sedans or coupe — as compared to t
Fastback
…will have a trunk opening that is separate from the rear window which remains in a fixed position. The term "fastback" is not interchangeable with "liftback"; the former describes the car's shape, and the latter refers to a roof-hinged tailgate that lifts upwards for storage area access. More specifically…
1973 Toyota Celica, one of the world's first "liftbacks", in this case a fastback-styled hatchback
Škoda Rapid liftback. Note how the tailgate is hinged from the roof and the rear window is lifted along with the rest of the tailgate. It is not a fastback as it does not have an uninterrupted slope in the roofline.
A 1974 Leyland P76. It can be considered both a liftback (the tailgate is hinged from the roof) and a fastback (the roofline is an uninterrupted slope).