So what we need then is a special designation on the dealer's road sign, much like the status that a Five Star rating connotes for Chrysler dealers we should have a "Double D" status for the dysfunctional dealerships out there. In fact it could be a universal status achievable by any and all dealerships regardless of marque. Achievement might not be the right word though.

Correct. And sometimes it depends on the customer as well. To put it bluntly, some people are a bit more believable than others. When I used to do electronics repair work to make extra money in College, I would ask people what was wrong and how it happened. Some people I believed, some were clearly not reliable reporters, and others were obviously lying about what they did to it, out of embarrassment or some other odd psychology.

I suspect the better SAs also get a feeling as to who to trust, e.g., I had an intermittent problem with my CD player in the Z4. They could not replicate it in the shop, but replaced it anyway. I suspect the report to BMW said they replicated the problem. I also suspect that if I had not given such a detailed written explanation of exactly what it was doing, they might have declined. (If it's in writing, they can pass the note onto the service tech, rather than depending upon the SA writing everything down on a service order).