I have had several problems with Hertz in Italy over the years so I avoid using them. This trip (I returned one week ago from Italy and France) I prepaid a car through Auto Europe, and unfortunately they assigned me Hertz. I told them I was dismayed I was going to have to use Hertz but no other offers were made.
To make a long story short, the Hertz car broke down less than 36 hours into the rental, and Hertz is claiming it broke down because I put the wrong fuel in it, and is charging me $801.60 for their "repair." The agent who rented me the car verified it used unleaded (senza piombo), there were no labels anywhere on the car (I have photos) saying to use a different type of fuel, and I only put 10 liters in anyway, but Hertz says, "You can't prove you didn't put in the wrong fuel."
The car slipped on some loose gravel as I was stopping and the orange car slipping icon lit up on the dash. The car stalled and would not restart. The orange light remained lit. The two policemen who tried to help even looked it up in the car's manual and said the relay had to be reset once this slipping sensor was activated. So Hertz is clearly trying to steal from me.
Most disappointing is that Auto Europe doesn't seem to want to help, either. I have spoken to several of their agents and even written to their CEO, but they say, "Hertz says you put in the wrong fuel. You can't prove you didn't."
To add insult to injury, Hertz took 17 hours to find a replacement car from me. Doesn't someone owe me for loss of use?
Be aware that you can purchase all the available extra insurance (as I did) but an unscrupulous company like Hertz can claim this and you have no coverage. I am still disputing this through my credit card company, Auto Europe, and even consumer activist Chris Elliott, but it doesn't look good. My future trips to Europe will not include a car rental!