We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Adrian saying something like:
F*ck, good point. Iirc, the vast majority of the time I steered or pulled towed cars they were actually legal (in that, they'd broken down or similar), so the question of that never arose. Mind you, that didn't ever stop me from doing exactly the same to s**te old heaps to the MoT /breaker /wherever. One could argue, of course (and it probably has been), that as soon as a car is towed it becomes a trailer and not subject to the normal car legal requirements.
Whatever; when I towed the Scim back here from Leicester via Wales, using an A-frame, I was passed on motorway by numerous cop cars and bikes and got nothing but the odd glance. Perhaps it was the Irish plates and they reckoned it wasn't worth the bother for no result.