I prepaid through Kayak. I got to the Hertz office a couple of hours after the designated pick up time, but figured it was not an issue since I prepaid for the entire reservation. I have had the same situation in the US and in Canada, so why should this be different? But it was. The agent told me that my reservation had been cancelled because I was over an hour past the start of the reservation, and that there were no more cars available. When I pushed back and said that the 'policy' which she was relaying was nowhere in my rental agreement with Kayak nor in any other experience that I had previously with Hertz, suddenly two cars were available, but both at a markup over what I already paid. I needed a car, so I paid it. I will follow up with Hertz as well to let them know of this issue. Buyer beware - Hertz in Paris (at least the 99 Rue Rivoli location) is shady!