I like the one on the bottom the best. My opinion is that a 3/4 view displays car models in their best light, as opposed to the side view.
I like the white backlight a lot, but my suggestion would be to try and see if you couldn't augment the back light with some "overhead" strip lighting above the cars to add highlights to the different shapes and colors. LED strip lighting can be bought with color temperature and dimming adjustment capabilities. It's my belief that proper lighting really makes collections of machines come to life.
I've been experimenting with my 1/18 scale model displays; There will be 4 of these shelf units against the wall. I believe this will be very close to the final configuration; on "lower" shelves, strip lighting will be installed about 1/2 to 2/3 of the way back, above the cars. You can see the proof of concept in black with exposed wires, , but that will all be hidden by plowing channels in each shelf with a router.
On the "top" shelves, I plan to mount framed vintage photographs with a gallery-style picture light up top to provide lighting on the cars as well as the photo.
I'm also experimenting with ID placards for each car. Jury is out on that idea, but it's nice to have a memory jog in my old age.
