Many years ago, I had a side hustle delivering pizza for Pizza Hut. Once they gave me a "bonus" of a free oil change at the local K-Mart; see, it was a long time ago! I normally do all my own automotive maintenance and repairs, but, since it was free, why not let them do it. Well, The "mechanic", I use the term very loosely here, said I also needed a new air filter, it had been a long time since I changed it so I gave the go ahead for a little extra money. When they finished, I got in the car, started it up and it seemed to be quite a bit louder than before. I drive it home, get out and look under the hood. The air cleaner cover was about a half inch higher than it needs to be to seal properly! The dope put the wrong air filter in! So I get on the ground and look at the oil filter and it was the same filter it went into the shop with, they never changed it! I took it back, asked why they didn't change the oil filter and why they put in the wrong air filter? Well, they went ahead and changed the oil filter and put the proper air filter in, but I never went back and never let anyone else do my maintenance, other than tires and alignments! Some bonus, more like a bone us!