As others have stated, OEM studs are fine with a 5mm spacer
however, i will say again:
5mm is barely noticeable and you won't be remotely flush
V2 Nismo body is the same as every other 370Z EXCEPT that the stupid little flares actually give less clearance due to how they are attached on the inside
save your cash and do it right
also, read this damn thing:
Wheel Fitment 101: START HERE