ChampCar/ChumpCar seems to be a breeding ground for spending some serious paddock time. I've been racing in that series since 2014. I've packed wheel bearings at 11:00 pm in 25F weather, etc. Some teams go to extreme lengths to get back out there and turn in laps. We lost 4 hours at a Road Atlanta race one year due to a failed fuel pump (dual pumps on an E36 - took us a while to diagnose and find a spare). Fun stuff.
Even the great ones have to work on their cars. Here's Randy Pobst troubleshooting an issue on his Volvo:
