Any person who tends to become closely aquainted with another person simply becuase they have a nice car. A car booty usually comes in the form a woman whose a "gold digger." A dude can be a car booty too, especially if he ain't got no whip.
Man, that bitch is a car booty! She just wanna ride in my whip!
The female counter-part to scrub, this person is deprived of any motorized transportation, and actively seeks associations with people who are motorized vehicle owners for the purpose of free transportation.
I thought this female was cool to hang with, but she turned out to be nuthin' but a car-booty.