>Years ago I always took our Blazer to a Jiffy Lube for oil changes. It turned out they weren't changing the oil filter. Eventually it stopped working and the engine broke down. $1800. Of course they wouldn't admit a thing.

Many years ago an Exxon crew replaced the oil filter with the oil change, added a new washer but left the old washer.
About 20 Kilometers later on the Autobahn the oil was gone between the 2 washers and the engine could be used as a nice door stop, but not much else... Got the new engine paid after taking them to court, as this was less than 30 minutes after the change.