Abstract: The invention concerns a roof rack for vehicles which is provided with a mechanism for extension (11, 2, 3, 4) permitting to lower the surface of manipulation for the load laterally of the car, in order to permit easy manipulations of all types of load which one may wish to carry on the roof of the car. During the lowering, the surface of manipulation remains horizontal. After the fixing of the load on the lowered support surface, the mechanism is lifted again and shifted over the roof of the car by a combination of horizontal and vertical movements and thereafter latched in its final position.