I have! The following evening I had another go – and got the tripod out this time.
I’ve re-edited the video (and the link on the posting above), exchanging the naffest shots for three- and four-car alternatives.
Now that I’ve seen the four-car unit actually trundling about I’m inclined to think it looks a bit too much, at least in my garden. Longer track and gentler curves would help. The USA Trains motorblocks (with a 12v battery-pack and Deltang set-up) have more than enough grunt and poke. I actually have to be careful.