With convertibles there is an increasing number of roof systems available.  These systems  are usually developed by the respective system supplier, and then, to make sure that everything actually fits, Volke takes care of the interfaces so that the system can be perfectly integrated into the vehicle.  This process begins with the adaptation of the body shell, continues on to the trunk lid construction and the layout and adaptations of the paneling and other coverings, all the way to the integration of the electrical and electronic systems.