I'd like to rent a car out of Bath and drop it in Oxford. Should I rent in the us? Are there any problems with this itinerary? Which car company?
We've had good experiences with Auto Europe, a US-based agency that connects you with companies like Hertz and Europcar. Their website makes it easy to compare options and pay by credit card, see http://www.autoeurope.com/. You make your reservation, they bill your card (but it's refundable if you cancel ahead, check the terms) and e-mail you a voucher which you present at the rental location. There may be a dropoff charge for returning the car in a different city, if so it will be built into your initial price.