I've just got back from Churchill college where I was doing some research, in their rather nice little archive. Now we all know of the Chaffee Race going on, well:

I asked permission to stick this up on the net, and their helpful archivist pointed out it was under crown copyright, not theirs, so ignore the little sticker.
Then when I get back someone pointed me towards this picture of a RAM:
I just couldn't get this classic comedy sketch out my head. I can just see one of the British guys saying:
"I look down on him, because he couldn't beat a Churchill tank."

Of course the US did some Tank racing, only they filmed it.