Jim, you are smart and I appreciate you sharing your knowledge about dealerships.
My truck club calls them 'stealerships'
A worker I hired in my small co. told a story about having dinner with his ex-girlfriends family who were very large dealership owners. He told me that he overheard a conversation that convinced him that Vehicles that are popular and easy sellers on the used car/truck market get the special treatment in the service shop...... motivate the owner to trade in.
This may be true at some places. I've personally only experienced one bad result of incompetence from the service shops I've been to.
However, I have heard of many horror stories with big bills attached to them.