I've sometimes asked Hertz to amend the contract to allow their European rental cars to go to Belgium, Switzerland, etc. with no problem and IIRC I didn't pay anything additional. These were often the cheapest Mercedes automatics.

However, Italy and parts of eastern Europe tend to be viewed very differently. IIRC Italy and parts of eatern Europe require taking Hertz insurance. Accident and especially theft rates are much higher in these areas. You won't get a free waiver for such regions.

If you have #1 Gold or higher, call Hertz. If you booked the car through a (real live human) travel agent, have them straighten it out. If you booked and paid through some website, you may be out of luck on this.