I have a home-brewed a frame.
It clamps around the lower torsion tube - works beautifully.
With the steering column unlocked, the wheels naturally follow the tow car as you pull into a turn.
It's a bit like if you just let go of the steering wheel when driving, the front suspension / steering geometry takes over & sorts it all out for you
We used it to tow a buggy across the country when i sold it. Far more stable than on a trailer (lower c of g, lighter, better suspension etc etc).
However......
We did get stopped once, and the traffic officer called up a VOSA rep to inspect what we were up to.
Basically, we got away with it as they had better things to be doing & we happened to be recovering the car from a breakdown at the time.
Personally I wouldn't try it nowadays
The annoying thing (for me) is that my Dad has an ideal tow vehicle & trailer, but being (relatively) young, my licence wont allow me to use it!
I need to just man up and pay for the test.