[Moneyguy1]

I had the same problem with an old 1977 924. THe water would build up on the sill and indeed damaged the cardboard door panel. The problem was too tiget a fit between the perimeter seal of the door and the opening. There was no place for the water to run out of and so it accumulated inside the bottom of the door itself until you opened it and it would gush out. I believe it is a function of the door settling downward over time, forcing the seal tighter against the sill. Since the driver's door is used far more than the passenger, this could happen. I rebuilt the bottom half of the door panel out of tempered masonite, recovered it with the original leatherette, installed new plastic sheeting for protection and cut a small groove in the bottom of the seal near the center. Since I had crank windows, the motor failure was not a problem. Measure the clearance on both sides between the door bottom and the sill and see if my theory "holds any water".