you can also remove centre console, glove box, headunits, speakers, vents, gauges that arn't used.
lighter gear knob, carbon mirrors (my stock ones are like 3kg each), body pannels, body kits, carpets, mufflers, cats, exhaust, alot of the useless crap in engine bay, mud flaps, extra bolts, front diffuser
find what you need: pedals, seat, seatbelt, steeringwheel, windscreen wiper/s, gearknob, handbreak, gauges.. everything else must go (interior anyway)
as also mentioned carbon tailshaft, performance + weight reduction in one.