sitting in your car bumping your jams with your homies after school in the parking lot but not driving. you just sit there and act cool with the windows rolled down. you want everyone to know how awesome your system is.
"hey guys, did you see jon and billy subwoofing in the parking lot? it was mad cool. they have a system."
When one sits around in a parking lot after school, blasting their car stereo really loud, subwoofers and all. This generally irritates those living nearby, who often will express their 'gratitude' by either calling the cops or reducing the number of functional body parts of the perpertrator.
That bastard Harvey was subwoofing from the parking lot next to my apartment last night. I was finally able to get rid of him when I lobbed an anvil at his car from my window.
The often inconsiderate action of playing a car stereo at full blast simply to annoy those around you. Typically the object is also to make the rearview mirrors of those around you vibrate in addition to your own trunk lid.
Yo, that punkass was subwoofing so fuckin' loud at the red light I couldn't see my own reflection in my rearview!