RE: Putting the automatic into reverse while moving.
If the VW auto in the Vanagon is built the same as Detriot iron autos of the
same vintage, the answer (if above 30mph) is nothing happens, same for the
Park position.  There should be a Reverse Blocker valve, actuated by
internal hydraulic pressure, that keeps the tranny from going into reverse
above about 30 MPH.  And the Park spall should not engage either.