Abstract: A hardtop for a convertible includes a front roof part and a rear roof part with a fixed rear window. The front and rear roof parts are operated by a lateral folding mechanism to be moved between a raised position and a retracted position in which the roof parts are contained in a roof box. The roof box is made variable in size via a foldable portion of the rear seat. When the roof is in the raised position, the foldable portion of the rear seat forms the rear seat. When the roof is retracted, the foldable portion of the rear seat is folded forward to enlarge the roof box. A shelf is attached to the foldable portion of the rear seat, which is an upper part of a backrest and is foldable about a horizontal axis of rotation to form a floor part of the roof box. The shelf forms a front wall of the roof box when the upper part of the backrest is folded. A roll bar is movable between a raised position and a lowered position. A roller shade box is disposed at a rear area of the shelf.