A name given to conversations had in a car at the end of a night out, in which events and goings on of the evening are discussed at length, along with the consequences of these events, people who are hated, people who are loved, the outlook for the future, and love and life and mankind in general; all the big philosophical questions. Often take place between the hours of midnight and 4am and can also be described as a "post-party debrief".
Person 1: God, what is my life.
Person 2: Look at your life, look at your choices.
Person 1: It's fine, we'll car conference it up later.
Person 2: Thank god for the motherfucking car conference.