My door glass saga continues . Ok so there are 2 runs in each door for . (the round bar that the door windows roll up and down on ) 2 of them have the bar welded all the way back on the bottom where you bolt them down on the bottom of the door . the other 2 have about 1/2 in of the bottom plate behind the round part . They have no good id on them to go by the manual . does anyone know which is the front run and which is the back run?