I noticed in my rear view mirror that they turned off the main road and went down a side street, so I just had to stop and see if I could find them. (Fortunately I was in good time for the class.) By some miracle, there was a parking space available on the main street, so I scooted off down a parallel side street and found the coaches parked in a residential street.
I only had the little point-and-shoot, but at least I did have a proper camera with me. I couldn't resist doing a sepia treatment. :)
One of the people travelling with the coaches had a tabard saying "Help for Heroes". My Google skills failed me for once, but a Flickr contact helpfully posted a link to explain what it's all about. That's quite an epic journey they're undertaking!
Here is the second coach.
And a rear view of the leading coach. If you look carefully, (click through if you can't spot them. I've added a note on the photo) you can see that there is a pair of fluffy dice hanging from the back. :)