Hi I do love that term master mechanic most of the time it means they were the best of a bad bunch, my daughters Q3 had full Audi service history and the telephone number bills with it, guess what when I dragged the filters out of it the air filter had the date the car was built stamped on it and the oil and fuel filter were indescribable, I wish you could talk to the garage owner I use he has removed loads of air filters and pollen filters from Audis that have the year of build written on them the crying shame is the cars are now 3-4 years old, the owners have a print out with whats been changed but in reality it has not they just tell people what they want to hear, BMW are the same the only dealer service history I would trust is Mercedes as from the couple I have worked on the o.e. part dates tally up, the Millers is a good product does what it says on the bottle.
Steve.