This was tried in quite a large premises back in the 1970s,I can't remember exactly where but Milton Keynes area seems to come to mind. They advertised that skilled mechanics would also be available to assist 'where necessary'.
From memory, it gradually turned into a conventional independent repairer. I think it had a catchy one word name. So memorable that I've forgotten it. Bear in mind that cars were a lot easier to fix in those days, although we didn't know it at the time.