I've looked into this with regards to Tesla (I'm on the fence about if I want to buy one or not).
I'm in Toronto, they're opening up a dealership in a mall ("Yorkdale" for the locals) and they have one service centre in each major city they operate in (Vancouver, Montreal, Toronto). The sales person told me they plan on opening more.
You pay $600 once a year for maintenance & service. Additionally, your car is constantly phoning home to alert Tesla HQ if something looks awry.
"there's no dealerships that can service your vehicle"
Around here the stealerships all claim to service anything you can push pull or drag in regardless of brand. GM service dept loves to service your Ford or Toyota, etc. There's no lifetime employment / company man effect, the greasemonkey at Ford probably worked at the GM or Toyota dealership last year anyway.
Finally, its an electric car, what are they going to do, change the oil and spark plugs?
The Tesla dealership near me (Seattle) turned into a service center. There's also a Tesla store in a mall nearby where I imagine you can set up the test drives and such.
At where I live car dealership only sells used car. If you want to buy a new car, you go to the manufacturer's dealership. Almost all of them are 3S shop: Sales, Service, Sparepart.
Allowing the manufacturer to sell their own cars works really well here.
In general fully electric vehicles are much simpler mechanically and need vastly less servicing. The bit of scheduled maintenance that they do need to be handled by anybody.