I would go back to where you had it fitted and ask them about it (do this purely because if you dont and you leave it too long they could consider it to be due to your driving style or any other excuse), you can log a complaint if needed in the future (date,miles etc)
BUT I know with the 370z a lot of people have complained about the burning smell from the clutch when they are new (not sure what is normal for this to subside though)
when you're driving in gear, how much travel is thereon the pedal before the clutch disengages ?
drive in 4th or fifth about 30-40mph and accelerate hard (best on a hill)...watch the revs rise with the speed (i.e.not slipping)
burning usually suggests - new or slipping
hth
Paul