I've thought about taking 2 3' ones and hooking them together. But, there would be a gap in the center and I haven't figured out how to get around that. The other problem with the current ones is that they don't hold very much. I spend as much time going to dump it as I do filling it. It's really bad in the fall with leaves, it fills up really fast.
Add a third one in the center behind the front two. I remember seeing this years ago probably doing school ground work