JTraveler.
As I explained in other posts automatic cars are not popular with Europeans.
All Europeans know how to drive manual transmission. Automatic cars have always been associated with people with disabilities and if you take a test on an automatic, the drivers' license will state that you can only drive automatic cars. Nobody of course wants that on the license, so everybody takes a test on manuals. Also since over 99% of people own manuals and kids learn how to drive on their family car, they obviously learn on a manual. It's really a vicious circle. Manual cars are also (IMO) more fun to drive, cost less and are more fuel efficient (which is very important in a continent where gasoline costs 3 times the price as in the US).
Since rental car companies keep cars only for few years, they need cars that can easily be re-sold in the local used car market, hence the reason why they keep very few automatics in their fleet and generally only on larger models. A rental car agent in Florence told me that Americans are the only ones who ask for automatics, therefore they keep those cars only at the locations that have a higher chance of having American customers. Brescia is obviously not one of them, I doubt most Americans have ever heard of Brescia. My suggestion is not to rent a car in Brescia, but rather to rent it in Milan, (either at the airport or at a Central station location) or in Venice, if you come from Venice. I'm sure they will keep some automatics in those two cities since a large number of Americans are likely to rent at those locations. Then you can return the car wherever you want, including Trieste.