If you look at the layout, and use it's scale (the Building is 200 top to bottom, and 300 left to right. So, take the Twister room, it is about 40x60. If the PR pics are to be believed, the cars are 2 rows of 4, and probably have at least an operating envelope of 10 x 10. But usually even more than that. So at least 30 x 30 of that 40 x 60 is the 4 cars. You can see the two lanes for the cars leaving the stampede, with something in between them, is about 40 feet wide. Add in space from the walls, and the fact that it is really a bit smaller, and some corners are curved, and you just don't have much extra room in there for other surfaces all over.
Point being, I just don't see many of these spaces having room for other surfaces for depth. And objects in the middle would be odd, since the projector putting light on it will also put light on you as you go in front of it, so it simply won't work. What is lined up perfectly for one car for it to look cool will look completely off for the other 3 cars. The multiple layers and depth are likely EXACTLY like Cinderella's Castle. THere are multiple surfaces, curves, and different layers. The projections will be mapped to the wall, and maybe just one section will change, and maybe that section looks a look closer to you, but there can't be much depth, or you would see shadows between them. Just like sitting far to the side of the castle.
It's going to be a good ride. But Disney doesn't possess magical powers. Very little they've done for 20 years has been ground breaking. SR's crazy PR pitches are being pounded by reality, and so will this and RotR. There is only so much than can be done with multiple cars. That's the whole reason Walt had the Omnimovers invented, so he could COMPLETELY control your point of view. Well, trackless vehicles are completely different. They have huge plusses, but they remove that POV control when done in large groups instead of one at a time like Spider-man (yeah, I know, it isn't trackless).