Load-carrier for a vehicle and vehicle with such a carrier

Horizontal bar members to fit automobile with two non parallel guide rails (12) on the roof. The bars can be adapted to different widths of roof guide rails by means of two link arms (41) which are fixed and pivot simultaneously on an axis (36) using a pivoting element (35) and two pivot arms, which in turn are linked to sliders (25), which are fastened and locked to the guide rails of the automobile roof.