re:  explain to me why VW trucks are not sold in the US when all the
Japanese makers bring us theirs

First of all, most, if not all, "Japanese" trucks sold in the USA are
made in the USA.  Question is better directed toward whether VW has
production capacity somewhere in the west, e.g. Mexico.  It may be
relevant to note that Mexico truck production is based on the '70s
Type II van, not the Vanagon and not the Eurovan.  Also relevant is a
check of current Eurovan prices in the USA.  USA truck customers
expect their "foreign" pickups to cost in the late teens, early
twenties, not the thirties.  Deletion of a couple of fuzzy seats and
some glass doesn't make up this difference.  Finally, in the USA, VW
is in the "cute car" business (whoosh whoosh)--there is no known "cute
truck" market--ask Subaru.