Where to rent car

It's not necessary to get a private car. Train and bus are both practical options from Florence to Siena, if that is where you will be staying. If you're staying elsewhere in Tuscany, there are other options. We stayed in Montepulciano and rented our car in Chiusi (also easily accessible by train).

We will be staying just outside of Siena for 4 days using that as home base. Traveling to Cinque Terre
and staying there 2 days then back to Florence to fly home. Trying to make it easy and not stressful. Returning a car can be a headache when departure is at 6:00am
Thanks for your advice

No need to go to airport to get a car- you'll pay a higher rate picking up there.
Pick it up as you are leaving Florence. We picked up at the Hertz Sansovino locatoin- super easy short cab ride from center and no ZTLs to worry about. Easy drive from there down Chianti Road to Siena.
We had looked into getting car in Siena but they were not able to guarantee an automatic which we needed.
If you don't need automatic and are going to Siena from Florence- rent it as you leave Siena. (As long as they can provide the size car you will need for 4 people plus luggage)
Take the bus from Florence to Siena as it drops you in the center (train is outside town).

Where will you end your time in Tuscany? Drop your car in Chiusi, Orvieto or wherever- no need to double back to your pick up location- unless that is the plan.

We always use AutoEurope for our European rentals- they are a US based consolidator with excellent service and usually the best rates. All drivers will need an IDP which you can get at your local AAA. Do your homework and read up on ZTLS, etc in Italy.

ETA-since you are staying outside of Siena I would rent as you leave Florence. Drop it before you go to CT- you won't want a car there. Train to CT then train to Florence.

"ETA-since you are staying outside of Siena I would rent as you leave Florence. Drop it before you go to CT- you won't want a car there. Train to CT then train to Florence."

^^^^^^^^^THIS!!!^^^^^^^^

Note: Siena is a tough place to find parking with a bunch of apartments down the hill from the center city.. I would do a day trip down there from Florence where the bus takes you right downtown. Buses line up on the block to the right of the Florence train station McDonalds..
Hertz on Sansovino is about a 2 mile taxi ride from the train station, and they can give you directions on how to avoid all ZTL's to get out of town. I check Hertz's frequent renter club rate vs. AutoEurope.com's rates.
You could turn the car in at LaSpezia and catch a local train into Cinque Terre. Then ride the train back to Florence if that's where you're staying prior to flying out.
We turned our Hertz car in at the train station location in Orvieto on our way to Rome.

After your Florence stay, when you are on your way out, rent the car in Florence.
Borgo Ognissanti is the street in the city center where all rental companies are located. Exiting the city center is very simple.
If you want to pick up outside the city center, Hertz has two convenient locations:
One location is at 53 Via Del Sansovino.
The other, even more convenient to reach the Chianti road to Siena (which I would take instead of the freeway), is located at 30 Via Ambrosoli, next to the Varlungo Bridge.
Your rental car return should be in the city of La Spezia, next to the Cinque Terre. After you return the car, take a taxi to the La Spezia Centrale train station for the short train ride to your Cinque Terre village of choice. The La Spezia rental offices are closed Saturday afternoon and Sunday all day. If your plans take you there on a weekend, return the car at the Pisa airport. On weekends only airport locations (and few others) are open.

Spare yourself and take the cheaper trains in Italy. I would not rent a car in Italy. You can take the train to Siena.

I would not rent a car in Italy. You can take the train to Siena.

OP is staying outside of Siena and wants to tour Tuscany towns. A car (or private driver) is needed and it's really not the big a deal once you figure out when to pick up and drop off.

Good point Roberto about Sunday closures. I always run into that problem when we rent in Europe. Sometimes makes us keep the car a day longer or drop at alternate location.

Spare yourself and take the cheaper trains in Italy. I would not rent a car in Italy. You can take the train to Siena.

I think you missed the part where they want to visit the small towns in Tuscany. It is very difficult to visit the small towns without a car. We had absolutely no problems driving in Italy and we would not have been able to have the wonderful experiences we had without a car.

Maryann, I have a few questions. How long will you have in each location? There are a number of considerations you need to make. With 4 adults, you'll need to pack lightly. Cars are generally smaller, even the SUVs. Personally, I don't think it is worth renting car unless you have at least three days to explore. I also suggest you stay outside Siena in an agriturismo.

Follow Roberto's advice and collect your car at either of the locations he suggests on your way out of town. Then drive the very pretty Chiantigiana Road (SR222 on the map) down to Siena. You won't make very good time but you really won't care - it's one of the most scenic drives in Italy and best enjoyed at a leisurely, meandering pace.
During our own visit this past May we never had any problem finding parking in the underground lot at the train station, which at 2 Euros per day is probably the best bargain in all of Tuscany. A series of escalators will take you from there up into the center of the city. Getting on the road in the morning is pretty straightforward for explorations around the region - it's only about an hour to Montepulciano for example.

Robert thanks for your advice. I will rent car in Florence and take scenic drive to Siena and park in underground parking garage. The B&B we are staying at just outside Siena has parking. That is home base for 4 days. We will visit the small towns at our leisure. The hotel in Cinque Terre also has parking available. Since we depart 6am on a Sunday we will drop car off at Florence airport late afternoon on Saturday. Take taxi to and from hotel to airport.. Does that sound like a good plan?
Maryann

My only thought (again, per Roberto) is that you neither need nor will you want a car in the CT - It would be more of a hassle than it's worth unless you plan to explore further afield beyone the 5 villages. Otherwise it's just going to sit there for your days in the area. Would probably save you some money and aggravation if you returned it in La Spezia.
As he also mentioned the dropoff at Pisa airport is very easy to get to, and from there the train to Florence SMN is quick and efficient. That way you wouldn't have to go anywhere near Peretola airport.
Other than that it looks like you're good to go.
Safe travels.