They do have their own counters in Italy, as mentioned before.
I once rented the smallest car and got a Nissan Micra.
As they have Smarts, they will give you one of these if you request a automatic transmission.
We Europeans don't enjoy automatics too much, so the chioce is limited and most of the cars have manual stickshift.
So just try to make sure you get the transmission guaranteed.
Just book your car via internet www.sixt.com and you can enter everything there. It may be the case, that not every size offers the possibility of auto-transmission.