Abstract: A roof wind deflector for motor vehicles having a stream lined design in aerodynamic respects, enabling an easy mounting and moreover offering a draftless and almost noiseless ventilation, which stands out for the fact that its front and sidewalls upon mounting are steeply towering above the roof of the motor vehicle, which walls gradually slope into an air guiding surface ascending in longitudinal direction of the car roof to the rear and ending in a raised flow-off surface, where the detachable fixture, being adaptable to various sunroof openings, comprises a sliding fastener arranged transversely to the longitudinal direction of the roof of the motor vehicle, with a sliding piece being movable thereon, which is connected between the wind deflector and, respectively, the motor vehicle.