How about dh do the car tour while you take the London Walks trip to Oxford (discount rail tix available)? London Walks promises to return you to London in time to get to the theater.

I was intrigued by the London Walks suggestion, but unfortunately, they go to Oxford only on Thursday, and our tour day is Friday.

As for spending the night before in Oxford, our London hotel is prepaid (one of those cheap Web excursion fares), and anyway that wouldn't help us with getting back to London for the play. In fact, we weren't really even planning to go to Oxford until DH found out about the Mini tour. So I don't want to give up any more time in London on this trip.

However, if anyone is interested in this continuing saga, I have found another alternative for the return, which I think will work better. I just discovered that we can get the cheap £10 "Apex" train fare if we leave Oxford at 4:06 pm instead of 5:15. So if we can get a taxi to meet us at the plant when the tour gets out (it's supposed to end at 3:15), we should get back to London in plenty of time for the theatre and even a meal. It looks like we could get to the Oxford rail station pretty quickly by cab, going around the ring road.