On a street car it's a pretty bad idea.

If you're building a track car where composite panels and windows are allowed, you can probably save a bunch of weight by switching to a CF hatch and lexan rear window.

I guess if you're trying to go for the "JDM" style bling (even though ViS is an American company) for a show car then it might win a point or two.

But yeah for a car that is actually used as a real car I'd skip it.