When I worked the parts counter, I had a guy come in and buy a starter for a Pinto. Guy that looked like a wrestler, giant - drives a Pinto. He changed it in the parking lot. People did that all the time. Somebody looks out the door and says "What the hell..." - that Pinto was rocking like an earthquake. Guy brings old starter in with a piece of the block and the 3rd ear cracked, bolt still there. He only took out two bolts, didn't see the other. I gave him his core charge back, no question. Boss says "We can't take that core, it's broken." I said "I'll give you $10 if you go tell him he doesn't get his $10 core refund." Customer drove away happy, register cashed out $10 short that day.
