8/10.
First, a bit of a reprimand. There is no point -- absolutely none -- in comparing this with TGUSA. One, the boys have had 7 years at this, while the Americans have had mere months. Two, when you consider things like the 24-hour-repair-a-road, the art-collection, the farming-tractor, and the afternoon-traffic-radio program, you will know that the TGUK boys can do worse -- much worse -- than the Yanks.
Second, missed opportunities. Perhaps doing the NASCAR Hall of Fame would have been too touristy, but I have trouble believing that the BBC wasn't able to get ahold of an actual NASCAR Car of Tomorrow for the boys to put through its paces. However, seeing the three cars selected go through the paces was pretty entertaining.
I'd actually have to say that Carolina and the New York City traffic race were definitely highlights.
Future America trips? Well, they really haven't done the Pacific Coast Highway thing, and I wouldn't recommend New England unless they used motorcycles (Clarkson on a DN-01, Hammond on a Triumph Bonneville, May on a Royal Enfield Bullet Classic). Seattle and Alaska are definite possibilities, though. And don't forget Canada and the John Cabot Trail.