They wouldn't be offering a VW. If they offered one it would be the Diesel from perf prod tech... who happens to be one of their dealers.
It's already in two or three tiges.
http://www.perfprotech.com/store/articles/marine-diesel.aspx Quite honestly, I doubt we'll ever see many diesel's until prices get more realistic. When they are charging between $20-$30K upcharge for the motor... it's just not feasible.
The VW mastercraft option is $27K