We have a BMW which is under their free maintenance deal too. In that case I know and am friends with the tech who I take it to, as we were both master techs at an independent shop back in the day. He's competent, and shares my annoyance at hacks who might touch and cause damage to our personal vehicles. So I let him do it, and visit with him in his bay while he does the work. I get to catch up with a friend, and he gets paid by BMW.