Abstract: An article carrier for mounting on a substantially flat exterior surface of a motor vehicle. The article carrier has two slat assemblies fixedly secured to the motor vehicle surface in a spaced apart, parallel relationship. Each slat assembly has at least one longitudinal rib. At least two pairs of brackets are provided, two brackets being removably and slidably fastened to the rib of each of the slat assemblies. A locking mechanism depending from the bracket is provided for securing the bracket in a fixed position along the slat assembly by clamping the rib between the bracket and a clamping member. One rail is supported by each pair of brackets to extend transversely therebetween above the surface.