Car rental

Check Hertz.com. Then check AutoEurope.com Very often, AutoEurope will be cheaper than Hertz, and you'll be getting a Hertz car. My best suggestion is to rent from a location in the city or outside the any airport. Car rental operations often place surcharges or have taxes on rentals that begin or end up there. The city locations can give you directions on how to get to your destination and keep you from going into the dreaded ZTL's.
Oh, yea! If you're going to rent from Hertz, join their frequent renter program for discounts on rentals.

I disagree, in part, with David's advice. Often, picking up and returning a rental car at an airport is a good idea, because you don't have to worry about avoiding ztl's. (If you don't know about them, and you're planning to drive in Italy, search this site. Very Important!) I've never paid extra to return a car to an airport. It's pretty easy to find out how much extra the pickup there would cost. We've always felt it was worth it for the convenience of not having to hassle driving in Italian cities.

It is unwise to choose a car rental company based solely on price. A review of travel forums will reveal many complaints with the most egregious concerning the budget operators. Rentals starting from airports are subject to an extra tax in Italy, as in many jurisdictions. The car rental companies also add a facilities fee which tends to be greater at airports.

We always use autoeurope.com because they have the best prices and great service. They are a broker and they use the major rental agencies. Our second choice would be europcar.com One recommendation is to purchase the zero deduction extra protection because the inclusive package insurance usually has steep deductions. Almost all credit cards will not offer car insurance coverage as a benefit in Italy, Ireland, Portugal, and Israel. After you've driven in Italy for a while you will understand why. Buon viaggio,

RE: "never have to pay extra to return at airport..." Yes, that's true. But you DO pay extra to rent from the airport or main train station. Sometimes it's worth it, sometimes it's not. Personally - the whole rental car idea is not worth it (to me) unless you're planning to stay in the middle of nowhere where trains/buses don't go. Rental cars add a whole other layer of aggravation including: petrol, parking, tolls, insurance, navigation (getting lost). Trains are so much more relaxing and you actually enjoy the scenery on your way to your destination.

I always thought car rentals were a pain as well, and while I'd never do them in a huge city (and we've only rented in France...prob wouldn't even consider doing it in Italy, well, maybe for the Tuscan area - but would rent again in France)...the freedom is nice - not to be tied to a train schedule, not having to lug your bags on and off trains/buses...being able to stay off the beaten path (we stayed with a wonderful couple in this tiny village in France that otherwise would not have been open to us without a car)...for us, we wanted to go to Mont St Michel, but without the train/bus hassle/schedule. Honestly, even with the gas and tolls and rental, for us, it was still cheaper and wayyyyy easier then taking the train/bus. We were very nervous about driving in a 'foreign' country, but I'm sold on it now and look forward to the day we can rent a car for a few weeks to explore France...and unlike a train, if you want to look longer at the view, you can stop, get out and enjoy...that being said, I love the effiency of the train system (and lament that here in Canada, our train system is awful...where it even exists)