"Carolina" covers a lot of territory...and several different kinds of sauce.
I think that line between vinegar/tomato in NC is actually a bit further east than what shows on that map.
Mike
Lexington BBQ is 'vinegar/spiced' and would fall right along that boundary. I grew up on eastern style as my mother is from far southeastern Virginia. Vinegar spiced and chopped with a couple of shots of Tabasco was the only way I knew for many years.