This? It's not the "World of Tomorrow". I think that really is Stark Industries. Or maybe Disney World. (Reality. It's so boring. Why confine myself like that?) It was actually the "Parade of Progress". Which I'd have seen on the truck if I'd been more than half awake. There's a Wiki article about it, HERE. And, a picture of one of the "Futurliners", as they were called, opened up for display, to give you the gist:
Harley Earl, so I'm sure they were intended to hark back to the roaring twenties, just like they look.