[carid]

We've got some lightweight carbon fiber parts from Seibon for 03-08 Z models. We measured the weight before shipping them to clients, and some bumpers and hoods were really twice lighter than stock ones. If you're interested in getting some certain CF part I can see what would be the weight.

 

[Matthew Doucette]

Does anyone know the reasons the base MT model gained weight over the years? For example, the 2003 weighs 3,188 lbs and the 2006 weighs 3,339 lbs. See a good chart on various 350Z curb weights here:
Weight Reduction Guide - Nissan 350Z & 370Z Wiki (older revision because wiki page was hacked)

 

[Rob Review]

There is some more information on this thread: Official 3point5 Weight Reduction Thread.