For we more senior citizens, it is important to note that many rental companies in Europe have age limits 70 years, but many have no such age limits. My wife and I somehow had missed the fine print when renting a car for use in Sicily, only to get there and find that they would not rent us the car we had paid for in advance. Fortunately Travelosity (or whomever we had made our reservations through - I don';t remember) was very helpful and got us a car through AVIS who didn't have any such age limitation.
Just be sure to check the fine print.
Phil