I always maintain my own vehicles; it helps that we have a very nice shop here at work with a lift.
However, a long time ago I was at Walmart... and they put the sporting goods section near the tire & lube area, so I saw a sign for a $15 or so oil change, and I thought; well that saves me messing with it in the weather and the price is the same - so why not? (their techs should be experienced, right?)
After noticing that the oil change was taking way too long, they finally told me that my drain plug was stripped out so they could not drain the oil, so they could not do the oil change... it was never stripped out before.
When I got in the truck, the hood release handle was on the seat, I went back in and asked to see the manager; who "had not heard they had any trouble", just that my drain plug was stripped. After him asking around someone fessed up that they had broken the handle, and then proceeded to close the hood once they could not remove the drain plug. Oh, and by the way - when they shut the hood they were not sure whether or not they had put the fill cap back on...
No one had a way to open the hood, but I needed to get home (which was not that far away), so I told them I would go ahead and try to drive it home and see if the fill cap was on by if it blew out all over or not.
They ended up paying a bill to the Ford dealership for replacing the hood release cable and the drain plug, and I ended up changing my own oil.
Needless to say, I've never been back.