Each rollout is a cabinet without doors turned on its back. Resize these cabs to fit in the base cab and you can place them inside the base cab while in the cab editor. It took some time to get the hang of it.
I made this to show a customer what a roll out base would look like. After finally having time to read the Ecabs manual I figured out how to play around with the presentation.
I know it's pretty basic, but I'm happy with it...