You will find in the arrivals hall near the exit all the major car hire firms including Avis, Hertz; Europcar and Alamo. If you wish to hire your car in the town of Beauvais then there are taxi ranks outside the main building to take you into the town where you will find Ada car rental. As this is a smaller airport you will find that the car parks that store the rental cars are all easily accessible and just a short walk from the Terminal buildings.