re:  If the Vanagon needs special tires why should we assume it can
use any
wheel?

This is the first relevant and rational post on this topic so far.

While I'm not sure there is a relationship between special tires and
wheels as suggested, until the facts are known there is also no reason
to believe Passat or any other wheels are acceptable.  Now I'm pretty
certain that VW is good at parts rationalization and if a particular
wheel is acceptable on more than one vehicle (and the styling is
correct), it will be used on more than one vehicle.

List members know that VW still produces the Vanagon in South Africa
and that (I think) it now comes there with 15-in wheels.  Are the
steel ones the same wheels as Passats or not?  If they are, fine, but
I'm relatively certain no one on this list is going to be able to
extract a go/no go answer from VW engineering in any event, and
evidence that the wheels are the same is going to be the only thing to
go on.

Here is another way to know with some certainty.  One of the
advantages enjoyed by owners of German vehicles is that they originate
in a society or culture where engineering is highly valued and one
evidence of that is that in Germany modifications such as this require
government (TUV, I believe) approval.  So, is there an
approved-in-Germany 15-in steel wheel for Vanagons or not?

PS
Someone has pointed out Passats and Vanagons weigh nearly the same.
They have not explained why Vanagons require reinforced sidewall tires
and Passats do not.  There is a difference between explanation and
suggestion, and I think "higher center of gravity" for Vanagons is
suggestion.  Folks are welcome to act on gut feelings.  Personally, I
want to rely on VW engineering.