Like Uncle Bob my list is long, but I'd say my biggest is the guys who have the car built, and then proclaim how they "built it from scratch" to anyone whether they ask or not. To be a "check writer" is OK, but then to tell folks how you built it, or how "we built it" when they just paid the bill at the end is pure arrogance.

Another is "Rat Rods" that are overdone, built purely for the shock effect and nothing else.