Carty - Car-ty
(K arr tee)

1) N - The act of partying within a car. Can also be used to describe a party held within a parking lot and in the close proximity of several fast food restaurants (Because there'll be that one person who is too good for Ronny Mac's Steakhouse). After ordering the food all of the cars converge in one area and the partying begins.
2) V - The act of attending a carty. 

1) That was one crazy carty last night!
2) I CARTY LIKE NO ONE'S BUSINESS

Derivatives - cartier, cartied out, life of the carty, etc.