There is a guy on youtube i stumbled accross watching 350z stuff that has stripped his zed out to the extreme but everywhere he can save weight he has. He is called thatbluezguy it will give you some ideas if you want to take things further. He claims to have the lightest 350 in the world. Obvious ones to start with are stainless/titanium exhaust, lightweight bucket seats, sports/decats, lightweight fly, remove spare wheel and jack.