A car without a roof is called a convertible
The roof
Sun roof
It's a car without a roof- a roadster
the headliner or roof
Turret
A freight car without a roof or sides is called a "flatcar." Flatcars are designed to carry heavy loads, such as machinery, vehicles, or construction materials, and are used in various freight transport applications. Their open design allows for easy loading and unloading of oversized or bulky items.
A convertible or a drop head or a roadster.
In the auto industry, it is called the "head liner".
convertible Drop head Roadster (if it is a 2 seater)
Some cars have those removable tops on them or the tops of the cars go back so it has no roof, which are called convertibles . As the car can change from closed top (roof) to an open top (roof).
A car that has no roof is merely roofless, but the name for such a car that has a retractable or removable roof is a convertible.
no <><><> The first car did not have a roof at all.