Well, all Coke products are Kosher, but Kosher for Passover Coke is only available usually the month before Passover because the HFCS is a corn derivative and thus not permissable during Passover.
So to all you non-Jews, please leave the Kosher for Passover Coke for those of us who actually need ("need" being a relative term considering Coke is a staple to some and not to others) to buy it during Passover. If your store has some in stock after Passover, feel free to buy it then.
I've never seen Mexican Coke before. Is it really bottled in Mexico, or is just one of those experimental flavors that they try every once in awhile?