Female Co-worker of mine (a mechanical engineer) went into to have a brake squeal checked out and was told that she needed new pads. This MIGHT make sense, but in this case the pads had less than 8k miles of wear on them.
She told the tech this and the response was "oh, it's normal to replace pads every 8-10k miles". After looking at the tech in shock for a brief moment she says "Go get your manager, I want him to be here when you tell me that again". The look on his face...priceless.