Five minutes into my first conversation with the General Manager, he asked me how much of a check he needs to write to reimburse my FIL for the overcharges. Since I only had 3 yrs. of history at that time I couldn't tell him as there was still 7 yrs that I didn't have. He also admitted (when i pushed him) the service writers make 10% of the dealership profit for each service sold. That's why my FIL said that when she recommended each service he told her to go ahead (Customer Requested Service) as she must know what is needed and he trusted her to know what she's talking about.
My ten minute conversation with the GM ended with assurances of their not intentionally overcharging or selling unneeded services and then offering again as to how much of a check they need to write.
I wonder how many hundreds of other customers this one dealership has done the same thing to.