car rental in Tuscany

You could call AutoEurope at 1-888-223-5555. They are very helpful. AutoEurope is an American based car rental co. for Europe. Some say they offer the best prices.

I say Autoeurope offers the best rates and, more importantly, the best service. Florence is probably the best to rent from unless you're going to be in far south Tuscany. Then, I'd train to Orvieto and pick up from there.

It's not so much the price difference between Florence and a smaller town. It's that the offices are likely to be open at more convenient hours and days. Also, the selection of cars will be better and the office staff more accustomed to English-speaking tourists.

Agree on Autoeurope. I just spent countless hours on the same scenario. You can go on their web site and try different pick up cities to see what is available. You could also consider Sienna. I did read one post that said there was a Hertz across the road from the train station, and Autoeurope will give options. If you choose Florence - make sure you have a clear path out of the city without driving in a restricted (no car) zone or you could see a hefty ticket in the mail later. For checking addresses of rental places quoted by AutoEurope, I've found the following site works well:
http://mappe.alice.it/tcolnew/index_alice.html#
Enter the city in the top left, the street below, and the street number to the right of that.
Make sure you understand the insurance and deductibles, some online quotes will be without mandatory insurance, or with very high deductibles.
I found most places had similar hours - closed 12:30 to 3:30, except Florence airport. Good luck!