Also in answer to Ali Dan Harry Albright is quite right about the best way to do it. The whole point is to avoid having to go through Swiss customs and immigration if you are staying in France. This is particularly true if you are coming from an EU country and remaining in the EU. There are baggage handlers on hand to fetch your baggage for you and it only takes a few minutes. In the meantime you are doing the paperwork for your car rental. I can guarantee that someone who went straight to the French side would have been in his car and on the road while Ali Dan was still going through French customs from the Swiss side. Going through Swiss customs and immigration is an unnecessary step. It's also quite easy to get landside if you find yourself airside. You don't have to ask anyone. Just go through immigration normally as if you were an arriving passenger out to arrivals and up to departures to check in. I often go back landside if I find my flight has been delayed as there are many more amenities landside.