This is the Steinwinter concept truck. It was actually built to show on trade fairs.
I've seen the real one in the early 1980's on a trade fair in Amsterdam.
In the early 1980's European truck manufacturers tried to build trucks that could transport cargo in the highest volume possible. These were called "volume combinstions"...The goal was to transport as much cargo for the lowest costs, usefull if you transport cargo with takes a lot of volume, but that's not that heavy.
The famous, or notorious Jan De Rooy (wellknown for his Dakar racing hobyy) used to have a lot of volume combinations, as he had a contract with Rockwoll to transport isolation products...
This resulted in trucks with the so called "topsleeper" and the shortest distance possible between the truck and the lorry.
see this
wiki article for more info about the Steinwinter truck
and, ABC magazine has also publiced a model of this truck, it came with the large trailer. The Steinwinter concept never passed European safety protocols though.....