Why doesn't Elon spin off Tesla Galleries as a separate company and sell it to SolarCity? Have SolarCity run them as a 'franchise'.
It's antithetical to what Tesla is trying to do.
If you're suggesting that he does that so that it's just like a dealership "on paper" but it otherwise behaves the same way it does today, then the dealership lobbies will attack it anyway, and they'll have additional ammunition because then what Tesla is doing is insincere.
It's much better to be upfront and honest about it, and push for change and win that change.