Also, if you are intending on renting cars rather than having your own, I think (but you may wish to check) that a lot of the rental companies require you to have held your full UK driving licence for at least a year before you are eligible to rent from them. Obviously you have your US licence for the first year, but after that, you can't legally drive on that licence in the UK, so if you don't have your UK licence you may have to wait another year after that before you could rent a car. Just something to check out/consider. I may be wrong as I am just going on what others have told me (I've never rented a car).