Renting Car for Tuscany, then Train to Rome?

I rented a car in Siena several years ago. I used Auto Europe but don't remember the specific car rental agency they used that year. But, it was very close to the train station. And driving in and out of Siena was relatively simple. It was the first time we had rented a car in Europe and we had no difficulties. I would not want to drive into or out of Florence.

Use a consolidator such as:
www.autoeurope.com
www.kemwel.com
(they are sister companies but check prices with both).
They work with the major rental companies in Europe. Select full insurance coverage (no deductible, aka "no insurance excess").
Select as pick up:
Florence - All locations
Select as drop off:
Rome - All locations
In all likelihood the best price will be with Europcar or Hertz.
Select the choice you want.
For Florence pick up location select Via Borgo Ognissanti (all companies are there). Hertz also has a location on via Sansovino, which is just outside the city center (not walking distance though).
The rental return in Rome should be at the TIBURTINA train station, which is easily accessible from the freeway.
If Hertz is the company you end up selecting, they also have an office in Orvieto. If you intend to visit Orvieto, that could be an option. Then from Orvieto it's a 70 min ride on the train.

I have rented in Florence downtown locations a couple of times several years ago. It took some practice to drive in and out of the city; picture scooters all around; fast cars; lots of narrow streets; etc. Driving in the hill towns, by contrast, was relaxing and fun. I am in no hurry to rent in the downtown again! Picking up and dropping off a car outside of the main city would be ideal. Not sure about the airport location; imagine that would be a reasonable option.

I have rented in Florence downtown locations a couple of times several years ago. It took some practice to drive in and out of the city; picture scooters all around; fast cars; lots of narrow streets; etc. Driving in the hill towns, by contrast, was relaxing and fun. I am in no hurry to rent in the downtown again! Picking up and dropping off a car outside of the main city would be ideal. Not sure about the airport location; imagine that would be a reasonable option.

The airport is on the opposite side of Florence if you intend to take the Chianti road. Also picking up at the airport usually carries a higher price because of the added airport fees.
The city location is a more logical choice, also because your hotel in Florence is likely much closer to that location than to the airport.
If one considers driving out of Florence challenging, then one should reconsider driving altogether.

Thank you to everyone for your tips and suggestions! I know driving in any city can be stressful but hopefully we can manage to make it out of Florence without any mishaps.

My fiance does not want to drive the car all the way to Rome from central Tuscany. Would driving to Arezzo to drop off the car then taking the train to Rome be logical ? I've been having trouble finding easy to understand train maps. Both Arezzo and Siena would be an hour drive from where we are staying. But I think Arezzo is on the main Florence-Rome line but Siena is not unfortunately. Is this correct?

Thanks again, you guys are great!

Going all the way to Rome is not that dramatic. It's probably 2.5 hours depending on where you are and the Tiburtina station is very easily accessible next to the freeway exit of the A24/Tangenziale Est.
Alternatives along the way are:
1. Chiusi Scalo (Europcar, Hertz, Avis)
2. Orvieto (Hertz)
Arezzo would not be a good choice, because you are back tracking.
Arezzo, Chiusi, Orvieto are on the old rail line to Rome.
You won't be able to catch a high speed train from these locations. The high speed Freccia trains run on the newer high speed rail line, which runs more or less parallel to the old one, but trains don't stops in those smaller towns. If you want to catch the high speed train, you need to go back to Florence.

I would pick it up at the Florence airport to avoid ZTL issues and would drop it at FCO or at an agency on the edge of Rome. Why take a train when it is so easy to drive to Rome; it just adds a layer of expense on top of an already expensive car rental?

It is a real shame to have only two nights in Chianti and south Tuscany. You don't really have any fat in your schedule, but I would drop one night in Rome so that you have 3 nights and two full days at least in Tuscan countryside. An added bonus of driving to Rome is that the stretch from the Val d'Orcia to Rome is full of wonderful things you could do on the way. e.g. there are Etruscan tomb sites near Sovana, the wonderful hot spring of Saturnia (I bathed in the waterfall which is a totally amazing place in a quick stop on a day trip in the region when we were renting an apartment near Siena) and Tarquinia and Cervetari just north or Rome have spectacular and quite different Etruscan tomb villages. Or even a stop in Orvieto would be lovely.

I have picked up a car before at the airport and it was relatively easy to just hop on the freeway and get out of town. I don't know how much more expensive it is than in the city center, but the risk of those expensive tickets are not worth it to me. You can then drop it right back there and take the train to Rome, or just drive to Rome and drop at the airport, again avoiding driving in the city. Driving around Tuscany is so much fn... it is beautiful and there are so many little villages and vineyards to stop at. I prefer villages so I would also take a day or two from Rome to enjoy Tuscany.

If you are concerned about negotiating traffic in Florence then spend a night in Siena and pick up your car there.
Dropping off in Arezzo and the slower train to Rome is a good idea.