Abstract: A roof structure (20) for an openable, rigid motor vehicle roof comprises a forward roof part (22), forward roof frame parts (24) laterally adjoining the forward roof part (22), a rearward roof part (26) and rearward roof frame parts (28) laterally adjoining the rearward roof part (26), wherein the forward and rearward roof frame parts (24, 28) are pivotable relative to each other about an axis extending perpendicular to the vehicle longitudinal plane and are storable in a position, in which their inner sides are oriented towards each other, and the forward roof part (22) is pivotable relative to the forward roof frame parts (24) and the rearward roof part (26) is pivotable relative to the rearward roof frame parts (28) about respective axes that extend perpendicular to the vehicle longitudinal plane.

Abstract: In a method for controlling the composition of a combustible air-fuel mixture present in a combustion chamber of a spark-ignited internal combustion engine having external mixture formation, at least two fluids containing air are generated, of which at least one is an air-fuel mixture; the fluids are supplied to the combustion chamber, wherein the quantity proportions of the fluids are controlled such that their total composition corresponds to the predetermined composition.

Abstract: In a tailgate for a motor vehicle, which comprises a lower tailgate body (18), on which a rear window (22) is mounted, on whose upper area a supplemental brake light (24) is provided, the rear window (22) is lowerable into the tailgate body (18), wherein the rear window, at least when the vehicle is driven, is lowerable only so far that its upper area provided with the supplemental brake light (24) upwardly projects from the tailgate body.