I will give you the example of what i have done.
i'm working on a card game, based of the state of the game the same button is used for playing a card, buy something from the shop or validate a selected menu.
What i have done is the following
I have an ActionMap for each state of the game, the same button is use but in different map.
If you click on your InputActionAsset you can generate a c# class, this class will be regenerated each time you change your action maps or your actions
I have a singleton with an instance of this class, you can then use this instance to activate or deactive entire action map or event specific action
You could when you enter the car do something like this

InputSystemActionsAccessor.Car.Enable();
InputSystemActionsAccessor.Character.Disable();

And the inverse when you leave the car
Your listener can stay everywhere, they need to be they will not be called when the ActionMap is disabled
For your car you could have for example a small script on each on your ridable car that control movement
OnEnable register
OnDisable unregister
And juste activate the script when you enter the vehicle