The exit window in our LR has just the release lever.....no screen. Along the bottom tho, the rubber seal is not 100% as there is what I want to say 2 areas where I can see light and Imo would act as drain holes but not sure. Haven never seen any evidence of water "back flowing" for lack of better words into these 2 holes, but am sure dust would not have any problem finding it's way in. Are the supposed to be there or sealed up completely?