Joel and everyone :),
Haven't been able to get any mechanic who knows anything about vanagons here.
 Not even the VW dealer will bother with me.  Infact they don't even sell the
new Eurovans.  This is info. I've collected on my own and with my dad's help
(he is a mechanic of domestics) we are trying to learn about this van.  I am
almost sure it has to be in the airflow box area beacause when I unplug the
airflow box and try to drive it-it does the same thing it does in the rain
(not always in the rain but 95% of time).  But what the heck do I know-I am
not a mechanic nor do I play one on T.V. My van has 52,000 original miles on
it and it has a lot of problems.  The oil alarm keeps going off (next
project) and then this "airflow problem" .   Vanagon list has been my main
source of info on my van.  Already spent $1000 on 3 different mechanics (one
was a foreign car specialist) and none of them could figure out the problem.  
It was a vanagon owner of 7 other Vanagons that told me to try and unplug the
airflow box to see what happens.  So I did and it replicated the problem so I
replaced the box and plug that goes into the box.  I don't know what to
think.  And apparently none of the mechanics do either.  The best thing I can
say is I am learning to do a lot of repairs to my van which is pretty darn
good for me who only knew how tho change her oil 6 months ago.

Stace