receive the bolt 29 the main body portion 33 has on its underside a downwardly projecting rib 35 extending across its lateral width as best seen in fig3 the rib 35 projects into a groove or recess 36 extending across the width of the body member 22 of the lower guide means 15 at each end the guide means body member 22 has a series of serrations or ratchet teeth 37 integral with the curved flange 34 on the end of each retainer means 32 is a vertical rib 38 having on its surface facing the serrations or teeth 37 on the guide means body member 22 at least a couple of vertical teeth 39 each retainer means body portion 33 has an enlarged opening 41 extending from the flange 34 wall to the rib 35 for a substantial portion of the width of body portion 33 to enhance the flexibility of the flange 34 in the area of the toothed rib 38 a belleville type washer 42 may be used beneath the head of the bolt 29 and the upper surface of the body portion 33 of the retainer means 32 the quick adjustment device as described permits rapid setting of the window panel 11 against the body seals when the vehicle body approaches the window fitters assembly line station the bolts and nuts holding the lower guide means 15 and guide bracket lower flange 14 in assembled relation are in a loose condition the window fitter is able to set the window panel against the body seal by merely pushing or pulling on the upper extremeties of the window panel from the outside of the vehicle.