The premise seems to be push down to the theoretical optimum. Too much shenanigans in the auto industry for that to happen.
If it doesn't discuss recreating 3D models of the Pillbug (from photos) and the Volkhart-Saggita (from the example in a museum), printing them on a 3D printer (carbon fiber/ABS, thanks much) and dropping them on a
Inrekor flat-pack clone of the VW floorpan; then it's a fluff piece.
(For the record. Of course you were the
first to mention it on Ecomodder.)
Edit: Google only finds
this black and white, but I saw a color picture of the door interior of the Rome-Berlin racer, or possibly the modern-day clone. It had oatmeal square-weave carpeting and a door pull that looked like it belongs in a theater lobby.