OK Karl.
So Germany is the same as the UK then - the rear seat in the standard or utility SW (as distinct from the two Belstaff SW) is moved forward 79mm to slightly enlarge the cargo area, add the mandatory barrier and like magic - you now have a "commercial" vehicle & significantly reduced annual tax (registration?) charge.
Whereas, for example, in Australia the determination of a "commercial" vehicle based on it's load carrying capacity; how much weight can it carry in addition to the passengers. This is why is Australia, South Africa, the US, etc. the second row seats are fixed the same irrespective of the three types of 5 seat SW.