The slaw I'm convinced is made of simply finely chopped cabbage that's left to sit in this same sauce until the cabbage is soft. And when you have a barbecue sandwich, you put the slaw on top of the meat. That's just how it's done.
Lexington Barbecue is on Business I-85 which branches off Interstate 85. I would definitely recommend it as a place to try authentic Lexington style barbecue.