Is there anywhere near Hendaye Station to rent a car? All of my searches have only turned up in San Sebastian or Biarritz.
Across the street there is an Avis rental office. Address: is 95 Boulevard du Général de Gaulle
If you take a short taxi ride to San Sebastian airport (actually in Hondarribia) you can find Avis, Europcar, Hertz and OK Rent a Car.