Yeah youd probably be looking at around 800 most the time but with some effort you could get lower. sound deadening can weight quite a lot, Decent lightweight alloys, I've saved 5kgs a wheel from that alone! The smaller things seats, steering wheel, manual windows or perspex instead of electric. Manual mirrors, Radio/speakers. Abs system, aircon, coilovers weight less than stock. Exhaust. Blah blah