A motor vehicle window panel or windshield has a lower edge portion with an attached extruded plastic molding having a downwardly projecting portion defining a cavity with an inlet gap for receiving a projecting fin on a cowl panel. A shipping insert of extruded substantially rigid plastics material supports the windshield and attached molding during shipping and handling and includes a base portion adapted to seat on shipping container support members and a tongue portion spaced above the base portion and projecting through the inlet gap into the cavity to support the molding. The insert also has an upper portion supporting a solid locating flange of the molding attached to a bottom edge of the windshield. The base portion of the insert has inclined opposite edge surfaces to facilitate sliding on the support members, and also has an upwardly projecting hook rib for retaining the insert on the molding.