Describing someone who readily engages in anal-receptive sex. Usually a gay man, but also can be a girl that likes it in the stink. Comes from the fact that most car's exhausts are located in the rear, and the anus is in the same relative place on a human.
The odds are 1 in 146,107,942 that you'll find a priest that doesn't take it up the tailpipe.
by Braveheart's thirst for blood July 13, 2007