Rental companies come in all flavors in Italy. Some familiar from the states and some different. You don’t want to get a car too big! Some small cities have very narrow roads and large cars wont fit through. Get used to cars are smaller in Europe. Gas is very expensive,. Last time I was there it was around $ 4 per litter or $ 15.40 per gallon. GPS works fine and can be gotten on your rental or you can use the GPS on your smart phone. Tolls are on all the highways or Autostrada’s They have an auto pay system similar to our EZPass. When I first started going to Italy, there were no speed limits. Today there are. Each lane has a different speed limit. The left lane is fastest, middle is in between and right lane is slowest. DO NOT HOG THE LEFT LANE! Italian drivers are fast and if a car is coming up behind you move to the right and let it pass.
Roads are well-marked as are exits. It is a good idea to have an understanding of where you are going and how far it is in kilometers. The roads have kilometer posts along their length. Italians drive on the right (correct) side of the road or for you Brits the wrong side.