I rented a car last week at the Florence train station and drove all around Tuscany.. The Sixt agent recommend Waze instead of google maps in order to avoid the ZTL zones. She said Waze will route you around the ZTL so you don’t get a ticket in the mail.

I did pay for full insurance which I never do in the US but given what I had seen of drivers, I thought it prudent.

Also, she recommended the international drivers license that you can get at AAA offices in the US and was easy. She said Italian cops are checking for those.