Dirty 'Cabin Filters'

This happened yesterday, Septmber 16, We took our car to a local quick change shop for an oil change. When the job was just about finished, the employee came in the waiting room with what looked to me like a dirty air filter. He says that it's a 'cabin filter' and it should be changed because it's really dirty. It was covered with dust and had a couple of tiny bugs on it. I said how much will it cost and he replies $49.99 but there's a 10% discount. Sounded to me like a lot of money for some fancy folded paper and cardboard. I told him to put it back in the car and I'll buy a filter at the store and put it in myself. A couple of minutes later he comes back in with another 'cabin filter' and says to the lady customer next to me that her filter is dirty and should be replaced. This example he held was even dirtier than mine. It actually had dirt and dust and plant material piled up on it. She also thought the $49.99 price tag was steep. She said her  husband can take care of it and to put it back in the car. Fast forward to our favorite AutoZone store where we bought a new filter for . . . $15.99. The parts store employee said that the 'cabin filter' deal is the latest way that oil change shops try to get more dollars from unsuspecting customers. So we get home and I start to change the filter. I read my owners manual and it gives the steps to do it yourself. Part of the process is removing the plastic cowl across the bottom of the windshield. So I approach the job and notice that said cowl is covered with Maple tree whirly birds, pine needles and other outdoorsy stuff that lodge behind the hood. If in fact the oil guy had pulled a fouled filter out of my car, all that old plant trash would have been knocked off the cowl and ended up in the oil change pit below the car. So I figure this guy didn't remove the cowl or my filter. The shop must have dirty filters for any given car that might come in for an oil change. That way the oil guy can pitch to any customer the dirty cabin filter scam. I have a thing against spending money at businesses that employ weasels with crooked sales tactics, so three thousand mile from now I'll find a new and hopefully honest oil change shop.