I'm on car-part.com all day, literally. There's a little trick most people don't know about on that site:
If you want a drive shaft (for example) and you know it will work for your project from any 350Z from 03-07 (but technically they won't because Nissan changed some little fastener or design detail which technically makes it a different part number) then do a search for a 1975 Nissan 350z driveshaft.
Obviously Nissan didn't make a 350Z in 1975 so the car-part.com software will bring up a new window asking you to specify a year range. Then tell it to search for 2003 - 2007 (if you know all those years will work for the specific part you want). It will then bring up all driveshafts for a Nissan 350z from 2003-2007 regardless of part number difference and interchange issues.
I do this all the time when I want a part that I know will work for my car even though the interchange software says it won't. For example, in 05 there are 3 different 350z engines. One for the 35th anniversary cars and two for the non 35th cars. But, I'd use either of them for a swap project so I do a search like above to see them all at once and find the lowest price.
Fred
Instrument Cluster and Speedometer Repair