1 - if I have a LN channel open with the dealership, and the dealership does not offer intermediary services, then the only use of that LN channel is to transact with that dealership. If the dealership is connected to a LN hub that I am not connected to, then I cannot transaction with that LN hub without the cooperation of the dealership, or I would need to route payments via other means to that LN hub via other cooperating LN channels.
That's why I suggest opening a channel not with the dealership, but with a hub, in this case.
This is why LN is banking. A few big hubs are the banks. Everyone will want to connect to them, and they set their conditions.