A double buttress folding top has rear-side tensioning bows with two rearwardly directed U-shaped sections that are connected to each other via a central bow section. The tensioning bows tension the folding top cloth in the region of the buttresses. The folding top cloth is fastened to the tensioning bow. The tensioning bow bears from below against a folding top compartment cover and against edges of lateral body cutouts. The folding top compartment cover therefore has two lateral cutouts which, in the open position of the folding top, are closed by lateral flaps. The tensioning bow is of U-shaped design and, above a rear window, has a bow web to which the rear window is coupled in a hinged or pivotable manner.