Abstract: A guide track for the window of a vehicle door can be adjusted vertically to adjust the location of a window stop on the upper end of the track to ensure a water-tight fit of the window upper edge and a weather-strip carried by the vehicle roof structure. Adjustment of the stop involves vertical movement of the track, up or down, preferably by loosening and tightening a track clamping-structure located at the lower end of the track. Access to the track clamping structure can be had through a small access opening formed in a trim panel on the interior surface of the door. Track adjustment can be achieved without removing the trim panel from the door. In preferred practice of the invention, the track clamping structure includes a threaded rod disposed between the track and a window support panel to swing the lower end of the track for changing the movement path of the window.