In places like that, there are a lot of foreign cars since business people who are not paying themselves don't really care where they leave the car. I'm not sure that this would work in Geneva since the rental companies can easily move the cars around, but sometimes you can be exempted from a foreign drop-off fee if you have a car from the country where you are going. This even works with a rental car that you are bringing closer to where it should be -- for example of you are driving from France to Italy and they have a car from Slovenia that they want to send in the correct direction. (In ancient times, I learned this when I worked for Avis for a year.)