Car Owners

What's getting to me is people who have no mechanical schooling thinking that they know everything about their vehicle. If you know what the problem with your car is why don't you fix it.
Also people who want to bring in their own parts for me to install on their vehicle. Do you bring a steak to a resturant and ask them to cook it for you?
And how about the people who think that if you work on their vehicle one time and some thing unrelated needs repair later on, you are responsible for the repair and should pay for because you worked on their vehicle once. Grow some brain cells people.