Originally Posted by BMW-M-Mexico
The finishing is not yet complete, this wheels still have to be shot peened etc... the seats do not of course save 100lbs per side, they save only about 20lbs total. The rear seats are refinished with lighter and less padding etc... and that saves another 23lbs I believe. Wheels and tires save another 28 lbs in all four points and brakes another 8lbs. Exhaust etc... in titanium saves about 38lbs. Fly wheel/clutch about 28lbs. Boot lid 11 lbs, new battery back 35lbs, plus a few other goodies here and there for the difference.
OK giving that a very generous 23 lb for rear seat padding you are at ~160 lb. What about the stuff that makes the car heavier. 200 lb net reduction would be great but again I don't see where it is going to come from.