A motor vehicle window regulator includes a helically wound wire coil on a flexible lubricating core to form a flexible cable, and the cable is confined within an elongated guide tube having a longitudinally extending slot. The coil is moved longitudinally within the tube by a helical drive gear, and a lower end portion of the cable carries a window lifting bracket or T-bracket having laterally projecting wings. A clamp unit is mounted on each wing and includes a C-shaped clamp body defining a recess which receives a pressure block and a U-shaped gasket for receiving an edge portion of a glass window panel. A set screw threads through the clamp body and extends through a hole in the corresponding T-bracket wing for engaging the pressure block to clamp the edge portion of the window panel to the clamp body. Each clamp body comprises a short section of an aluminum extrusion and defines slots or grooves receiving edge portions of the gasket and the T-bracket wing.