If you want to be really comfortable when you are driving around Europe then why not hire a motor home. They can be rented through all of the major rental companies so should be available to pick up at airports. It really makes life fun when you can pull over on the side of the road and make a cup of tea or have a nap. Imagine being able to carry everything you need with you and not having to worry about finding accommodation for the night. A great way to explore a country in a relaxed and civilised manner.