I hope I don't get kicked off this forum forever for admitting this. When I used to work at a cafe that served a great many European tourists, we would every so often get someone that would order a VC. We came to find out that it stood for vino and Coke although the snootier of the barristas insisted it still meant water closet. I seem to recall that the tourists that usually ordered it were Northerners (Sweden? Norway?).
At some point my girlfriend and I decided to give it a try, both being fans of red wine and Coca-cola (separately). It's definitely an interesting combination and Thomas is absolutely right that it depends very much on the qualities of the wine (good wine not necessarily making a good match). From that point forward, whenever either of us orders a glass of wine in a restaurant that is not particularly good on its on, we order a coke and mix them.
"How's the wine, sir?"
"It's fine. Could I please have a Coke as well?"