Its pretty much like that for any car, a guy I know was drifting his XR6 Turbo a few years back at Symmons Plains and a head honcho from ford australia happened to be driving past the track, saw it and wrote down his VIN and put a nationwide void on warranty for it.
Even little things like fitment of lowered king springs and aftermarket wheels can void warranty, so im not at all surprised at the GT-R having these kind of terms.