bubbletop

or bub·ble-top

[ buhb-uh l-top ]
/ ˈbʌb əlˌtɒp /

noun

a transparent dome, usually made of plastic or bulletproof glass, that serves as the roof or part of the roof of an automotive vehicle.
a vehicle having such a dome: The old van was converted into a bubbletop.

adjective

fitted with such a dome: a bubbletop limousine.

Origin of bubbletop

First recorded in 1965–70; bubble + top1