It's always been difficult to hold a conversation with my partner while
cruising at highway speed in our ’81 Vanagon. (I know what you're thinking,
you guys need a councillor).  But no, it was the wind noise. I did notice
one day that the noise reduced significantly if I pushed out on the
driver's window.   Checking the front window felt strip the rubber seemed
hard and there was not much felt pile left.  Probably the original at over
40 years old.  I replaced the driver's side felt strip, P/N 251 955 453D,
and what a difference it has made.  Conversations are now very easy.  The
passengers felt strip is original too but is less worn and does not seem to
be causing a problem, maybe because the passenger window is not used as
much.

I looked at some online videos on how to change the felt strip before I
started and it seemed like you just pulled it down from the top and up from
the bottom. However, my seal was held in with contact adhesive. Easy enough
to pull out from the top but no way was the bottom going to pull out of the
door.  I even pulled a muscle in my arm trying.  I was surprised that the
seal did not just snap, I pulled so hard. I decided not to pull the door
card off and remove the window but just splice the new seal against the old
as low as I could in the track.  Managed to do it just 1/4’ above the lower
window seal with a clean butt joint.  You have to look very hard to see the
join.

Just thought I would share this finding as it made such a difference in the
wind noise for only a few dollars and an hour's work.  Of course there is a
downside, I can no longer use selective hearing and blame it on the wind
noise.  Something that probably can’t be fixed by a counsellor for a few
dollars and an hour of my time.