You need to adjust the upper window stops(2 of them, front and back) so that the window doesn't go up so high and not go under the lip of the seal when the door is closed.

I had to adjust them on my 280CE a few years ago.

slightly loosen the 10mm mount bolt and move the stop in small increments and tighten the bolt and test it out.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg