One time they put a new carburetor in my car - it was out of gas.
Reminds me of the time I had a rattle in my dashboard. I took everything apart in the front, including the fuse box, and put it back together meticulously (I am woman! Hear me roar!) but still couldn't get rid of the rattle.
Finally I took it to the shop and paid to have them discover it was a tin of mints in the console.