I like to switch up my rolling stock often. I wanted the cars stored track side but still out of site, somehwat dust proof and very easy access. The unit stores under one of my layout wings and is on casters so it easily rolls completely away fo doing wiring.
It has four shelves that fully extend out 6 feet. Support legs are hinged sturdily. They fold up and stay out of the way hed by magnets. They only have to be used if shelves are pulled out more than 3 feet so I will keep favorite cars in front. It will hold about 175 cars. Now I simply pull out drawer and swap consists trackside.
Another problem I used to have was filling my yards with too many cars making it very hard to have fun making up consists on the layout. Now I just grab some cars and remove to shelves.