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A girl who pretends to be crunk just for the excuse to hook up with a guy in his car. These hookups tend to be a one time thing, and they never conversate again because of strange things the girl and guy did that would be embarrassing to discus. Usually this is a mentality of a group of friends rather than a single person.
Andy: So I left with her after the party and we just hung out.

Sarah: Yeahhhh, don't lie, everybody knows that she is a backseat rider.
by Hahahano April 04, 2006
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