Basically the 350Z has no cold air ducting to the front discs from either the front bumper or from underneath. Odd decision because it's a heavy car and even a Nissan Almera has ducting to the front discs. Maybe have been aerodynamic reasons.
A couple of stops from motorway speeds are all it takes to get the discs and fluid piping hot.
Maybe 'hot' but with uprated discs, pads and fluid as Roo had even repeated hard road use should still not cause 'warping'.
Personally I would be getting a second opinion if any garage said my discs were warped when it hadn't been tracked and such a set up had been fitted