Derived from the hotbox, this is when u wait till your entire family is in the car and its raining outside. Once on the highway you fart you fucking brains out but cant open the windows due to the rain outside. All in the car die from odor as you laugh like satan spawn
When you fart in a car with closed windows and the smell is so vile that the windows fog up and an undefined ectoplasmic substance accumulates on all surfaces.
Fat Abbott was Fartboxing his vehicle with such incredibly rancid bombs that he projectile vomited all over his ugly asssoccer mom SUV. His passengers weren't so lucky and all perished.
Farting in an unventilated area typically under a blanket to either cause distress to the next person to use the area or to enjoy the gassy goodness of sulfur and methane for ones pleasure.
Kyle: It smells so bad in here
Ben: But no one has been in here for the past half an hour!
Kyle: They must've been fartboxing