I never understood why they couldn't make this work. It would be entirely digital.
Compared to the real-time render tech used on Smuggler's Run, it surely is a much simpler problem to solve.
The design/display stations run Unity, a game engine. Set up 6 large-scale projection walls throughout the attraction, have your cars render at full scale on the projection walls, and treat it like any other digital effect - just rendered on the fly.
Assets for the engine would need to be upgraded, the current models and textures are sufficient on the small scale they currently are, but blown up larger-than-life would look far far worse than a modern mobile game.
The biggest issues would come from stability - last I checked, Unity doesn't have great (or any) implementation on embedded platforms, and desktop OS's aren't neccesarily stable compared to their embedded counterparts. The Design/Scan stations run Windows 10, and while they're not ride critical, I most certainly have seen one or two down each time I'm there.
Of course, to do all this, they'd need to convince management that 1) It needs the work, 2) it needs the budget, and 3) the park can survive without it's most popular attraction online for however long this would take. So it wouldn't happen.