Their is people looking into making a turbo kit for the NAV. However to date I don't believe anyone has installed one. However their are people with a turbo accent that is fairly similar to the 1.6L NAV version. So its more than possible, just not much research has gone into it like the accent..
i'd be interested to see if the exhaust flange is the same.. if it is.. then a couple months down the line the shop i'm working with for the FMIC setup is talking about maybe doing a manifold for the VT..