If you are serious about getting rid of that much weight...strip all of the interior out, carpet, seats, door panels, cut the dash to only hold your instruments, headliner - everything. Then get rid of the heater and a/c. Then get out the plasma cutter, remove all of the extra sheet metal inside and outside the car, including the bumper bars. Throw away your doors and hood, get aftermarket fiberglass ones. Get rid of your headlights, turn signals, etc. and replace them with a 0.040" thick aluminum sheet metal with a decal replica. Take out all of your glass and replace it with plexiglass. Strip off every piece of beauty molding you can find on the car. Strip out the execess wiring harness that you don't need any more becuase you took out what connects to them. Now get out the plasma cutter again and start looking for other things you don't need - becuase now you are down to a racecar. Get rid of the alternator and get a smaller battery. Get rid of the stock fuel tank and replace it with a lightweight aluminum fuel cell. You have a start...
Kirk