I started with a well used Schwinn kid trailer, stripped it down to the frame, then bolted and screwed some scrap wood to it to support a plastic cargo bin. The two gray ones I screwed to the cross pieces were the only thing I had. I plan to find bigger containers that will cover the available space on the trailer. I'll probably still go with two because it's easier to manage the load with compartments. I'll also add something for visibility on the back.