Welcome. A few things I can think of are the arm rest and center piece around the shifter, roof liner, sun visors, blower motor, climate control, door pannels, a pillars, switch windows over to manual ones, delete crusie control that will take a few pounds off. And if your wanting to get crazy I've read a few magazines where they drill out bumper supports, replace door windows with Plexiglas. Once your done with the body you can turn to the motor. Lightweight exhaust, intake manifold, flywheel.
Also why do I keep seeing GSRs with b16s? I just don't get it.