If you have a westy , you need to be concerned about unhealty vapors. I
tried a felt material from a junked american vehicle,but it unglued fell
down and jammed the window mechinism.Made a nice sponge to hold water. I
ripped it out and used a spray undercoating on one door. I could get all
the nooks and crannys without tearing my hands to shreds(a vanagon tight
area first?). On the other , I used a sound proofing material,backed with
aluminum foil. Both doors ,when slammed, sound like a  heavy,luxury
american car.Water draining down from the window needs exit holes at the
bottom of the door.