Too many cars ended up on the floor in my sons search for the "exact" one he wanted to play with at that moment. I turned to the internet and found a few solutions. This One in particular was the closet thing to fast, easy and possible. We changed it up though. For his car shelves we spaced 7" between them to put Action Heros too. We used 2 x1 and secured them with screws to the studs. The link has the boards painted white, but you could paint them any color or leave them the plan wood. It was very fast, the big box stores will even cut them the length you need.
