It is not allowed to return a cambio car in another city or at another station. A cambio car must always be returned at the station where you picked it up.
We made this decision very consciously. If we were to allow our cars to roam freely in the city, we would be creating more inner-city traffic to bring the cars back to the places where they are needed the most. We aim to create a more pleasant and healthier environment; to make or to stimulate short inner-city displacements does not fit in our vision.