This solves many of GMs problems. They don't have an easy means to rid themselves of an excessive number of dealerships. However a sharing system can effective

This solves many of GMs problems. They don't have an easy means to rid themselves of an excessive number of dealerships. However a sharing system can effectively do that; fwiw I have little if any issues with the dealership model and i drive a TM3! it also insulates them from having to make appealing vehicles, they have already proven they cannot do so in the sedan market and have effectively abandoned it. snark aside, they are already experienced in selling to rental fleets and have put together packages for cars that suit that market very well while not appealing to regular buyers