For starters - unless you're going to do a good pro job at spraying your wing, I strongly suggest you shouldn't.
Secondly, it's up to everyone's personal taste, but a duck wing on a GTR is a no no in my opinion as th GTR wing is sexci - also, the GTR and the GTST have the same boot size, hence if you look at pics of the D-wing on a GTST it'll look the same if it's on the GTR.
Someone's already asked a similiar question - check it out:
http://www.skylinesaustralia.com/forums/Gt...61#entry3316561
Good luck - but I personally think the GTR wing is tuff as...