It appears to me to be CGI. Certainly is very cool, though ingress/egress would be nigh on impossible unless the roof tilted up.
Indeed it is, MMC design did a few weird concept designs on CAD a few months back & some original framed prints were auctioned off for charity.
There are a small number of classic MTW in the UK that survive with a small van rear, I think Harrods in London had one in the 40's
