I doubt that just the R would get the Nav, it would most likely be R/GTI/GTD all getting it if any. It really wouldn't cost them much to do, seeing as most of the hardware is in the standard unit, just a module to add. When VW used to charge £280 for electronic diff on the Scirocco and it was fully selectable in VCDS for nowt, I doubt they'll be giving much away with BW45.