I saw a web video a few years ago. It was a towing and loading demonstration using a small model car towing a small model trailer over a variable speed belt.. It was produced by the engineering department of a British University.
They were showing how the trailer load could be shifted fore and aft thus producing sway. I think it was at a trade show.
Anyone know where to find that web site or video?
I have searched the heck out of youtube and google.