It is very rare for concept vehicles to make it into the mass production line.
some ware along the box line, aerodynamic eats up on load capacity.
just like the the tail skirts we see now days in used by the good O'l ATA carriers (paid for largely by tax payers grants), they are not after fuel saving as much as they are after shoveling LHV's via the back door (so to speak).
here a real quiz for all of you engineering minds.
ever notices how almost all of euro's TT have no gap at all between the truck and the trailer, and here in North America most of all TT have around 3 foot gap ?
how they do that ?