The guy at the repair shop kept going on and on about muffler bearings. He handed me a few bearings to show me what they looked like. I paid him a fortune to replace mine. It must have been a simple repair, because he was done in no time at all. He was very nice and friendly. He was laughing and smiling the whole time.
I thought I would repay his generosity. IANAM (I Am Not A Mechanic), but I figured I could help him out. I walked over to his car, opened up the gas cap, and dropped a few bearings inside his tank.
He'll thank me later, I'm sure.