I didn't read this whole thread but it sounds like we're looking to plumb
an intake?   This may be silly but in my inline motored van the intake
tract is made from aluminum sprinkler pipe...irrigation sprinkler pipe,
about 3" diameter and it works well, is durable and it can be welded if you
are any good.  You can buy the appropriate silicone connectors around the
internet..
  Another option is brake air duct hose...it's available in the racer
supply houses...that is what I am currently using for a fresh air
snorkle...it comes off the air cleaner intake with a hose clamp and I
fished it up into the right vent D-pillar, bent it 180 at the top so it
won't catch rainwater....this stuff has a spring inside it to keep it
'inflated' and if it works for racecar brakes, it's ok in the engine room
of a van...fairly inexpensive.

On Sun, Aug 3, 2014 at 11:34 AM, Chris S. <szpejankowski@gmail.com> wrote:

> Here is a picture of the intake bellows and airflow sensor.  You are
> looking from center onto left opening behind taillight.
>
>
> http://i16.photobucket.com/albums/b7/misterpolak/Misc%20VW%20nuttiness/5141E9E0-1B59-4546-B3F6-60A4B8272832_zpsubkibher.jpg
>
> The cost of CEET hose for 6 feet is around 60 bucks. It's very durable. I
> would be looking at a 180 degree turn and a run along the rear wall between
> tail lights.
>