I don't have the issue with the screw, but I can say that with these windows (you have the same ones I do) water will get into that track when it is raining hard. However it should/usually drain out via the weep holes and/or just sit in the track. So I'd say step one is to make sure water from the track can't seep into the coach/ply like that (well, obviously step one is to fix the rot, but).
This is separate from whether or if the windows themselves need re-bedding to the coach fiberglass walls. I'm only speaking of water in the track where the windows slide and where the weep holes are.
I've read numerous other reports of this particular window (and maybe others) allowing rain water to come into the track (which then drains out through the weep holes and goes bye-bye). Oddly, mine only does it on the driver's side window. It seems to come in at the interface of the forward (vertical) end of the moving panel and the track. I haven't looked too hard into whether I could change it since it does drain back out (it only comes in with a fairly large volume of rain).
Sealing Side Windows
Re: Sealing Side Windows
1999 Concourse
