Parking in Naples

Two easy options:
1. Google it.
2. Go to viaMichelin.com and navigate to a map of Naples.Click on the parking icon below the map and it'll show you locations from which to choose.

Good luck! Have you driven in Italy before? Great for small towns and Tuscan, Puglia etc but Rome to Amalfi? You may want to reconsider. IMHO

There is great public transport between Rome and Naples, see Naples ( lock luggage at Naples Centrale) in high season take ferry to Positano/ Amalfi, off season train & bus, or driver. It is a crazy drive.

Good luck!

Park at Naples Capodichino airport. Easy access from the autostrada. Then take the Alibus into Naples. Time 1 min.
Cost E 3.

Edit: bus takes 15 min.

From Rome to Amalfi you'll drive first on the A1 divided motorway, and then on the packed and slow "Costiera". Both aren't more demanding than a country road in Tuscany.
Naples is another story, just don't.
Don't drive there and do not leave anything in the car. If you really want to see Naples either take the train or park at the airport as suggested above.

Are you sure you'll need a car on the Amalfi coast in summer? You run the risk of wasting holiday time driving at 40 kms per hour behind buses, while ferries would be quicker and less stressful. Driving the Amalfi Coast is actually very funny and the views are breathtaking for both the driver and the passengers... if you do it at 6 AM.

the bus from the airport to the centre of Napoli takes one minute????

You seem to have made your decision already, but the fast train to Rome will give you more sightseeing time in Rome. Bought well in advance, the tickets could be less than a day of car rental and CDW. Don't leave anything visible in the car during a stop in Naples or anywhere.

I'd drop the car in Salerno, then fast train to Naples, then fast train to Rome. Driving will just waste time.

Also, I had better pizza in Rome (Trastevere) than in Naples.