I
ALWAYS visit the restroom and the customer waiting room with a walk through and then walk out to my car. I stand, kneel or sit as close to the yellow plastic chain to see everything they do with my car. I'll make small talk with the grease jockey in the pit.
I have been known to bring my own synthetic oil and filter depending on the offering and just have them do the work.
My last oil change Mystery shop was at a Goodyear. They opened the cover and added windshield wiper fluid and then pressed too hard on the centre of the cap and cracked it in half! Yes, the car is older and the plastic was brittle. Superman was not laughing like I was when he did this. He saw that I watched him break the filler cap. He went right to the shop owner and told him that they need to call the dealer and buy a cap for me before I could even say something. The dealer on the other side of town sent the parts truck there for one $5 cap. They called me about four hours later and I drove up and popped the hood and they put the new cap on.
If I was not watching, How do you think this would have turned out?
I also had a coupon for a free rotation with oil change and needed one. I made sure they used a torque wrench and quizzed them on the ft pound measurement for that vehicle. Then they removed the brake drums that were rusted on for over four years and adjusted the brakes as well. They were glad to see me leave.