We are travelling from the UK for a holiday in the outer banks early July and will be renting a car from Washington DC to drive down across the Chesepeake Bay Bridge Tunnel and down to the Outer Banks. The end of our holiday will involve a bit of a road trip right down to Ocracoke and back up to Washington DC at the end. Our problem is that we are spending the majority of the holiday with some family from the US who are renting a beach house in Corolla which i understand is only accessible by 4x4. The problem being is that none of the car rental companies in Washington will guarantee us a 4x4 will be available. They say we can rent a mid-size or full size SUV class car which may (or may not) be a 4x4. Someone else has told us that "all wheel drive" is no good and it must be "4 wheel drive". can anyone give us some advice on this? Also, will we need to book the ferry in advance to get back to the mainland from Ocracoke? We have already booked our accommodation but any other advice would be most appreciated!