I took my wife's car in for general maintenance. Oil change, fluid check you know the fun stuff. I refused the air filter change because of all the maintenance that needs to be done that is the easiest and I would save some money doing it myself. When I went to put in the new filter I noticed that they not only didn't latch down the air box lid, they removed the old filter. This is highly unprofessional and yes I know mistakes happen. But unfiltered air can cause irreparable damage to an engine. I am glad I did the filter change the same day. But this has taught me to go back and do as much maintenance my self because at least I'll do it right.