Eric,
I'm with you on the water leak issue.
I noticed the floor under the carpet was wet when I was running wires to
install my accessory gauges.  I foolishly dismissed the water as normal
dampness from water and snow from my shoes.  I completely removed the carpet,
dried it out for two days in the house and re installed it.  The following
summer, I noticed the foot well on the passenger side stayed wet days after it
rained and the carpet in that area stayed wet for weeks.  Hmmmmm.  Now I was
sure the water was leaking from somewhere around the front of the van.  Last
fall, in an effort to stop the leak, I replaced the windshield seal.  The
carpet and the footwell has been dry since.  I used what The Bus Depot called
the California model windshield seal that is solid rubber and does not have
the plastic chrome trim in it.
Replacing the seal was very easy.  It's a big piece of glass so it did help to
have my brothers' assistance.  Anyone who's interested in my previous posts on
the subject should check the archives.
I supposed seal lifespan could depend on many conditions.  My van started out
new in Virgina, then went to Washington State, then to Florida, then to Maine,
and now back to Washington State. The previous owner had replaced only the
windshield once and I've replaced it twice.  The old seal was stiff and
shrunken when compaired to the new seal.

Best regards,

Andrew Martin
'87 Vangon GL Syncro
177K
Poulsbo WA

Andrew