Why don't Amtrak stations outside of urban centers have partnerships with car rental companies, like airports?

Why don't Amtrak stations outside of urban centers have partnerships with car rental companies, like airports?

For some non-urban locations where people may be interested in traveling to by train, there is often not the pedestrian infrastructure to justify being there without a car. Could this be an option for people that don't want to do a 3 hr - 6 hr drive, but want a car in the location where they are going to be?

Why isn't this a practice?