A car is not strictly necessary to travel in the area as there are trains and buses
that can take you almost anywhere. Nevertheless I would say that renting a car is very
very strongly suggested because local trains and buses are very slow and their schedule
is often disattended: you will end up wasting a lot of time.
If you rent a car I suggest that you do it from your country (Hertz, Avis, Dollar or
whatever you are used to) specifying the exact period, where do you want to pick it up and
drop it. In other words you don't have Italian branches of car rental companies apply their
fares which are usually much higher than other countries'. You can pay the car in Italy with
a Credit card.
If you want to rent the car from Arezzo, the only company is:
Avis, Piazza Repubblica 1/A, Arezzo 52100 (just in front of the train station);
tel. +39-0575-354232.
If you want better fares, try Dollaro Express (but you can pick the car up only in main cities/airports:
Rome, Milan, Florence, etc.) which is part of the Holiday Autos international network.
Their address is: Via Simone De Saint Bon, Rome 00195;
tel. +39-6-3701108;
fax +39-06-37353335;
e-mail dollaro@uni.net;
Internet address
(with prices, other info and on line reservation): http://www.dollaroexpress.it/dolleng.htm