cartop

[ kahr-top ]
/ ˈkɑrˌtɒp /

adjective

of a size and shape suitable for carrying on the top of an automobile.
Also car·top·pa·ble [kahr-top-uh-buh l] /ˈkɑrˌtɒp ə bəl/.

Origin of cartop

First recorded in 1945–50; car1 + top1