don’t jinx it … original motor + original tranny ftw 
i did have the rear axle clicking problem pre-tt, but for some reason it’s gone now with the tt (weird). i also have the infamous 3rd gear grind, but very very very infrequent (maybe once every 2 months), but for some reason my z whistles at highway speeds between 120-130 and ONLY between those speeds.
lots of little quirks with the 03’s, had to replace both my driver and passenger power window motors, but it’s the first gen 350z, so you’d expect these kind of little quirks, none of which were that serious in my case.