Not sure if this helps, but my car has five bolt adapters that are seriously thick, like 2 1/2 inches and 2 parts.  I am not sure the wheels I have (they were on the car when I got it back), but I assume they fit the 350Z since they are NISMO wheels.  The rears are 8" and the fronts are 7" (so I was told).  I think they are zero offset (again, so I was told), but with the thick adapters, they fill my flairs pretty well.  I am not sure where the adapters came from, but if you want to know, I will try to find out.  If any of this is wrong someone feel free to correct me.  BTW, I am not sold the the whole adapter idea, but the person I got the car from said they are safe.