You could get a carbon fiber hood and/or carbon fiber trunk lid. Obviously could strip the inside and take out the back seats and such but that kinda destroys the car... You could take out the Air conditioning system... that saves some pounds but sucks when its hot out. just some thoughts
aluminum bumper beams and control arms. CF driveshaft. swap in the manual windows and locks from an L. thinner windows off a R/RA. ditch the A/C, cruise, etc. strip the interior. get some Prodrive CF rally seats. rebody in either FG or CF. you get the idea.