Fiat rental

I doubt it--we've always been prepared to take whatever we are offered (within reason) and I just assume that is the industry standard. Luckily our switches have usually been an upgrade--though we did have to nix a BMW once, as my husband had not driven a stick in so many years and his first driving trip in Italy was not going to be the refresher. Oh how we laughed at the guy's reaction to us turning it down!
If you use Autoeurope, they provide a nifty chart of their offers, perhaps you could do some narrowing down of choices there?

do you mean a vintage Fiat 500, from the 1950s?

Or do you mean a modern car?

YOu'll need to search for a specialty company, I"m sure they exist so do some Google. This is not something you're going to get from Hertz or Enterprise. You could also look for places that rent Vespas, they would probably know their automotive counterpart.

I think the OP means a modern Fiat 500. The alternative offer will probably be something like a Toyota Aygo X, Hyundai i10, or a Citroen C3 / Peugeot 208. All decent small cars. I've been doing some research just this week on cars in this class for my mother who is replacing her Vauxhall Corsa (Opel Corsa on the continent). Skoda Fabia or Seat Ibiza is my recommendation to her. Very similar VAG group cars to the Volkswagen Polo, but slightly cheaper.

In my experience selecting the car in smaller European markets is just a suggestion. I reserved a Fiat 500 at the Avignon TGV rental and they excitedly told me I got a free upgrade to huge Mercedes I didn't want and we settled on a horrible brown Citroen SUV that felt like driving a top heavy shopping cart. Or ask my friends about reserving a Mini "or similar" (since he loves Minis) and then ending up driving on the Autobahn squished into a Smart car.

I not sure I've ever actually gotten the car I "reserved" in France, Italy, England, Ireland or Spain. Although I haven't rented at a large airport where the selection may be less constrained by what's actually come back versus the smaller locations.

Good luck, hope you get your Fiat,
=Tod

PS It's not always bad. The Alfa Romeo SUV was a much larger car than what I reserved but it was awesome to drive.

I hope you get a Fiat, but in my experience you get what is available. However, at the rental site try and get what you want. We had the opposite happen to us from an upgrade. We signed the paperwork and then had to go to a different location to get the car (this was in Rome). The car was a smaller one, barely enough room for us, never mind luggage. Back the rental office. First response was that there were no other cars available, we stood our ground and got the car we paid for originally.

Whatever car you get, inspect it carefully and note any damage on the rental forms and take pictures. We liked to get a car with a few kilometres on it as invariably they had some damage, so upon returning it, there was less concern. We had one case when we returned a car in a dimly lit underground parking garage. The attendant signed off the paperwork without really looking at the car as it was so dark.

We found it very easy to rent a Fiat on Salina a few months ago. From a small, local agency. That's the only car they had!!

I imagine you might find one at a small agency in Puglia, but just check the various companies. Ours was a Panda, I'm not sure if that is the model you would like. It was a semi-automatic.

You are always going to come up against that "or similar" clause.