RE: Storage
From what you are saying I think you are talking about the carriers that go
in the hitch on the back?  Never used one but friends have.  The
complication is that the wider ones need to be wired up for tail lights/stop
lights, their wide enough to block the lights on the Vanagon.  And a front
carrier is going to hurt your gas mileage.  And bad packing of items in the
top luggage carrier up front can also cut your gas mileage, don't ask how I
know :)
And part of the solution is what you pack, you really don't need all that
you initially might think you need.