21 day trip

I would look at dividing your time somewhat like this ...
Sicily - 6 days (Palermo-Catania-Taormina-Messina)
Naples/Amalfi Coast - 5 days
Rome - 4 days
Florence/Tuscany - 6 days
Is this what you had in mind?

I would only consider car rental in Sicily and Tuscany.
Return the car at Messina on Sicily and board the ferry/train towards Naples.
Choose Sorrento as your base to see Naples, Pompeii, Capri, Positano, Amalfi.

I second what has already been suggested. A car wouldvcertainly be handy in sicily and tuscany. If u stay in an agriturismo u will not hve a prob parking your car overnite.

For me, it's not practical to do this route by car. You'll spend a lot of money on parking (and paying for a rental car that's parked for days on end) and you won't save time overall. Using David's itinerary as a start -

I'd spend a little longer in Sicily. It's very big and there is a lot to see and you arrive jetlagged. You may want a rental car for some of the time, depending on what you want to see.

Fly to Naples, then base in Sorrento, which has the best connections (train, bus, ferry) to other places in the area. Driving is difficult, you are much better off using public transportation.

Train to Rome where you won't want a car either. Then train to Florence. You won't want a car to see Florence if you stay in Florence. If you "commute" from an agriturismo, you'll need to park outside the historic center.

Caveats You don't say what time of year you are planning to go or what your main interests are. That would make a difference in my suggestions. Allow time in the itinerary to travel from place to place, whether you're using trains/planes or a car. Subtract that from the time you have to spend in each place. Rule of thumb: x nights = x-1 days. Sometimes you get an extra 1/2 day, sometimes less.

Sounds great!!! Do you recommend staying in the agritourismos for the whole trip? I think it is a great way to immerse in the culture.

Again, it depends on what you want to see and do and what time of year you're going.

Haven't decided on a time of the year yet. Would like to go when crowds are less. Recommendations??? If we were to stay in agritourismos ,wouldn't we need a vehicle to get to them? Really would like to immerse ourselves in the culture and explore

Haven't decided on a time of the year yet. Would like to go when crowds are less. Recommendations??? If we were to stay in agritourismos ,wouldn't we need a vehicle to get to them? Really would like to immerse ourselves in the culture and explore

At this point, I think you need to read the RS Italy guidebook. Agriturisms are fine if you want to spend your time in rural areas to relax and hike or to take day trips to nearby towns (where you'll park the car and walk - like Siena and San Giminagno in Tuscany), but most of the places you list are cities in which a car is an unnecessary disadvantage and which would require a medium to long commute from an agriturism.

I don't have a clue what you envision by "immerse ourselves in the culture and explore."

An agriturismo can be a great place to stay if you are seeing small towns and rural areas, and yes, you will need a car. But an agriturismo is not a good way to see Rome or Naples, just as a farm stay is not a good way to see New York or San Francisco. Stay in a central hotel or pension in those cities, and try not to have a car during that time (you will only be parking it, expensively, during your time in big cities).

I stayed at a great agriturismo in central Sicily, but again, while you could commute to Palermo from there, it's hardly ideal (and you really don't want to drive around Palermo). So, start in Palermo, then pick up a car for other parts of Sicily. Drop it at the Catania airport and fly to Naples. Unless you want to see places in southern Italy like Calabria, flying is much better than driving from Sicily to Naples.

Here's my review of the Sicilian agriturismo: https://community.ricksteves.com/travel-forum/italy-reviews/sicily-caltanisetta-central-sicily-agrigurismo

Car in Sicily and Tuscany is great, be sure you have the parking figured out before hand. Car in any larger Italian city is a waste and can be dangerous to your health.

You want immersion I have a suggestion. Find a villa in a town and stay with the Italians. You can do that in agritourismo but you are on a farm and remote from people. We have rented villas in, and close to, towns and loved it. Two come to mind, San Gemini in Umbria (Pallazo Santi Terzi), and San Gimignano (Villa Arnilu) in Tuscany. You can easily do day trips in your rental car from these kinds of places. From San Gemini you can easily jump a train to Rome (out of Nari) and from San Gimi (Poggibonsi) you can catch trains to Florence and Siena.

Thanks for all the suggestions. Looking to do this trip in the fall of 2016. Looking for places to stay where we can use it as a base for 3-5days. Taking day trips and returning. So far I see us flying into Siciliy and renting a car. Satying there fro 4-6 days then flying to Naples then taking a train or bus to Amalfi Coast and Capri. Maybe staying a few nights there then training to Rome and Florence. In Florence rent a car to travel Tuscany. Return and fly out of Florence. Does this sound doable?

Your new plan is much better. But realize that Sicily has a lot to see, so even with 6 nights, you will have to be selective.

molto bene !!