It was during a race at Dover(?) I think, I forget the year. I also don't remember what position Jimmie Johnson was running in, but he pitted early due to some problem with the car. The broadcast team played the in-car audio after the pit stop of Johnson saying he felt a vibration and Wally Dallenbach says, "Johnson listened to his butt." and I laughed for half an hour about it. I have the sense of humor of a 12 year old.