Answer:
It is basically a slang term for asians.. originally used in the Korean war when U.S. soldiers would run over the Koreans leaving tire tracks on their heads.. but it has other meanings too, I heard if you part your hair down the center you could also be called this.
I think dude's guessing.
It's the way we buried them, head to shoulder down the line. A zipper of heads!
As for a slang term, sure their potential.