A structure and process for forming a window guide 102 integrally formed with a window run 4 applicable to an automotive vehicle in which the window guide 104 is formed by means of injection molding with a molten resin. The window guide has an extended portion A of a substantially U-shaped cross section, the extended portion A may be made uniform in thickness without sinks and/or weld marks by provision of a thickness reducing portion during moulding. An end edge 7 of the extended portion extends toward the outside of the vehicular body. <IMAGE>
