A former coworker owned a VW Golf that had a manual transmission. He took the car to a quick oil change place and upon leaving his clutch began to smoke and deteriorate very rapidly. He limped the car back to the oil change place to find that the 'tech' who 'serviced' the car saw a plastic cap near the transmission. He removed the cap and for whatever reason thought that some sort of fluid must need to go into the opening. The cap was an inspection hole for the clutch........the idiot dumped a bunch of brake fluid in the hole. It got a bit ugly with the manager, but the guy got a new clutch in the car at the expense of the oil change business. That is enough to keep me out of those places.