I don't get when people get into a loud-idling vehicle (probably with some anti-muffling adjustments), start it, and then let it run without moving for half an hour before driving away. Every day. Does their car/truck/suv really take 30 minutes to warm up before it can drive anywhere?

Other times it's loud vehicle sound systems. I imagine the person inside either isn't aware how annoying it is or doesn't care that they're broadcasting bass to the entire neighborhood.