3 to 6 people sitting in one car parked in a commuter lot engaging in activities such as chain smoking, drinking, recreational drug use, listening to music, talking shit about people, and sometimes casual sex. Usually a last ditch effort to get fucked up without having a place to go and the bars are lame. Often frowned upon by the unitiated. Usually they last until the wee hours of the morning.
"Had nothing to do last night so we just sat at the commuter lot for a car party and listened to "Midnight City" by M83 on repeat and got blackout drunk."
Drive around while drunk (designated driver of course) and bump music and have lots of girls in the car wit you and just be hella wild!
Last night was crazy bro, Car Party! We drove around like six hours from Seattle to WC to Des Moines drunk just being hella wild! >=)