Though not a Vanagon, several years ago I took my Mercury Capri (Australian)
to a Wa*M**t for an oil and filter change.  The running gear on this car is
Mazda 323...nothing out of the ordinary.  Thirty minutes after entrering the
bay, One of the techs came running in looking for a manager, and went back
out.  There were now 3 of them surrounding my car.  I finally got them to
tell me that they had drained the transaxle instead of the engine, and
couldn't figure out how to refill it.  They wouldn't let me near the car,
and wouldn't hear of letting me check the Ford service manual which was in
the trunk.  They tried to refill it with 90 wt. gear lube through the drain.
On this car, you remove the speedo drive connector and there is a dipstick,
and the hole is the filler.  They got it full of gear lube, but this 5-speed
uses ATF!  Talk about poor shifting!  Cost them a tranny overhaul (about
$850)!