GPS display in rental car

It probably depends on the class of car you get. We reserved the lowest class and I think they upgraded us up one. It was pretty bare bones: no AC, maybe an inch between me and the car door and a USB-A outlet.

No display. I think a vent mount from the dollar store would do.

It was pretty bare bones: no AC

When and where did you get a car without A/C?

When I've rented cars in Italy recently, I've asked for a car with Gps installed, and have always been happy. I often drive alone and want that extra navigation help.
If you do not care about one being installed in the car, it should be very easy to pair the phone with the screen display. To be sure, you should ask the agency.

I rent directly from Sixt..highly recommend that agency.

No guarantee that the specific car you will receive has a GPS built in (many do, but plenty don't, and if there is, sometimes they want to charge you to use it); also no guarantee that the car will have a "screen" at all (many do, plenty don't)...always remember, you get the car they have, so any promises or expectations about the specifics of your car are not binding.

Yes, many cars have easy integration with your phone, so often you can see it on the built-in display - but again, not always, so don't count on that - it all depends on what car you get, and that's almost always a roll of the dice.

To be on the safe side, bring along a car mount from home, for your phone. I always have one with me when I plan to rent a car (once I forgot to bring it, good thing I had a roll of Gorilla tape with me, which was ugly but it worked...). I've rented cars overseas probably more than a hundred times. Only once (in the Faroe Islands) did I get a car that came with a provided mount for my phone, which was a pleasant surprise. Don't count on one unless you bring one yourself. Get one that's versatile, works, and know how to set it up before you leave from home. A small roll of good, strong tape (I like Gorilla tape) is good to have even with a car mount - sometimes the mount is floppy and unreliable, and the tape can help make it work (be super careful not to damage the car dash with the tape).

Your phone's nav apps will work best if you have cellular service - without service, it'll be limited.

All cars I have rented in Italy in the past few years, in the subcompact SUV or Compact car segment (for some reason all Jeep Renegade or Jeep Compass, probably because Jeep are made in Italy for the EU market) had CarPlay and a decent display.

I’ve not rented an economy segment car for a few years, so I don’t know if economy cars have the same, but if you do rent an economy car, be ready to know how to drive a manual transmission car because nearly all Economy size cars come with manual transmission only.

When I've rented a car, I've never seen a video connection via Bluetooth, only audio.

You're looking for Apple Play or Android Auto. The cars I've rented in Europe over the past 3 years have all been equipped with them, but we don't rent bottom tier vehicles. I'd ask at the rental counter to make sure you get a vehicle so equipped. You might have to connect the phone to the car with a cable, though Bluetooth connectivity for Android Auto is increasingly available.

Joe52,
I rented a car from Europcar in Sorrento for 4 days starting last Tuesday. It was a Fiat Panda, 5 door (I thought I was getting a 3 door). It was pretty zippy and I enjoyed the drive on the Amalfi Coast very much. This is why I have clung to my manual transmission car and my daughter now drives stick. It was €90 and cost me €13 to top up the gas.

No air conditioning but had the windows down on the way back. Fresh as a breeze!

I barely use air conditioning at home and mine had been broken for a year or two before I even noticed. Got that fixed before an August Banff road trip a few years back.