There is a rust mark on the inside of the door frame in exactly the same place on both sides of the car that have me stumped. It's only light surface rust but I can't figure out what's causing it. The doors shut ok and don't lift or fall as they open/close, which seems to rule out the hinge pins. The rubber stops are fine and the seals don't stick - in fact on the drivers side they could do with being a bit tighter to the frame. A couple of pics below show the rust spot on the frame and a corresponding mark on the door seal itself.