[DutchmenSport]

If you've ever watched the movie, "The Long, Long Trailer" with Lucy Ball and Desi Arnaz, they used one of these tow dollies to tow their trailer. (although theirs was a support wheel under the frame). The concept is the same. They've been around a long time. Different sources keep re-inventing them. How well they work? well, ??? I've never know anyone that actually used one.

Double tow semi-truck, like UPS and such, used something similar under the second trailer. When it's attached, it looks like a 4 wheeled wagon. But it's actually a 5er dolly.

One thing to consider also, some states might consider this "double towing". In Indiana double towing is allowed, so it would work here, but not sure if it would pass the gravy somewhere else?

And if I used one in Indiana, with my current 5er and my current tow vehicle, I'd be way over-length for my state requirements.