Seems to me a few years back some folks here were talking about finding Mexican Coca Cola.
I can't locate that old discussion. But bottom line IIRC it was mostly available in the mainly agriculural areas, such as western Palm Beach, Davie, Homestead etc - where you find many immigrants.
Well for what it's worth, I found it yesterday right here in east Delray. At Publix, in the soda aisle, mixed in with the "specialty" sodas (photo).
So go get some of the real sweetener - sugar!