notchback

[ noch-bak ]
/ ˈnɒtʃˌbæk /

noun

a style of back for an automobile in which there is a sharp vertical drop-off from the roof line to the trunk.
an automobile having such a back.
Compare fastback.

Origin of notchback

1960–65; notch + back1, on the model of hatchback, fastback, etc.