In Nice, France, we went to the Hertz office a day before to confirm our car rental for the next day. After checking our order, they said the automatic car was broken and they only had manual cars available. We emphasized that we couldn't drive a manual car, and they said there was nothing they could do. The issue was not resolved satisfactorily.

It's okay.

When we arrived at the store, our reserved car was no longer available. There were only two cars left, an Audi and a Volvo. They gave us the Audi, and later, when returning the car, they tried to charge us for a vehicle upgrade, which we refused to pay. When picking up the car, the staff told us that returning the car with less fuel would be calculated accordingly. However, when we returned the car with two bars less, we found out that if the tank is not full, they charge for a whole tank... This resulted in over 1000 RMB extra.

I originally booked a French car, but it was changed to a Japanese car. Later, I paid extra to switch to a smaller German car.

We needed a GPS for navigation, so we paid extra to upgrade to a Mercedes B180. However, after getting the car, we found that the built-in navigation didn't work, so we took a TOMTOM navigation device from the store. When returning the car, we were only charged for the vehicle upgrade and not for the navigation device. That was quite good.