The glass is inserted into the rubber, and into the metal channel perfectly evenly all along the window.

The car has been in the family since brand new, and it never sustained any damage (I have the "window-sticker" and every repair invoice since day one).

The was one place I thought I could "cheat" by raising the glass a bit in the front end of the channel, but alas, the channel isn't deep enough to be able to raise the front end of the glass in it enough to make a difference. If I could get the glass up in the channel at the front end, about the most I could safely go would be maybe 1/4" at most, and even then the glass is REALLY tight in the channel (I tried making it move and couldn't).

When I "rock" the glass while watching the pivot at the "X" of the regulator arms, there is a bit of "play" at the pivot. Not much (at the pivot), but enough that when "multiplied" by the length of the arms, the front of the glass is about 1/2" lower than it should be.

I would think the mechanisms should last a "lifetime" or Volvo would have built some adjustments into the system to compensate for wear. Certainly well under 100,000mi for a Volvo isn't "lifetime" so I am sure you're right that it should not be "worn out" at this point.

After spending a lot of time looking at the door w/ the inner panel removed watching the mechanism move, and while hand manipulating the glass, just getting the back 1/2" lower, or the front 1/2" higher (by shortening the rear arm, or lengthening the front arm) would solve the problem (I would just leave the slight play alone), or I could remove the regulator and re-build the "X" pivot point with zero play, leaving the arms alone.

Unfortunately, I have the tools/equipment to do either, but not where the car is (AZ), so I guess for now I'll put up w/ it as I have for a while now, though the wind noise on the Interstate is unpleasant. I hate to give up (surrender), but I think at this point it's the wisest move.