There is no 'goodwill'
The dealer I took my wife's car to is the same that I buy most of my parts from so the service people don't know me. After they told me the MAF was bad they asked if I wanted it changed to the tune of $500! Of course I told them no and took the car.
The next day I returned to the same dealer and spoke to my parts guy who sold me the MAF unit for $238! It takes all of about five minutes to change the part needing only a screwdriver.
Of course the service writer checked the car's records to see if it was purchased there which it was not so attempted to put the screws to me. Obviously I did not bend over for them!
End of story and will not pursue through NHTSA etc.- this time.