This should be easy.
With some Arc8 wheels + non-runflats, you'll save ~15lbs/corner for 60lbs weight savings total.
Get the HPF or VRSF exhaust (single 3.5" style) for a 35-40lbs weight savings over dual exhausts.
Take out your rear seat when you go to the track for 54lbs weight savings.
Get a Braille 17lb battery and mount, 32lbs weight savings.
Next get a pair of Recaro Speed seats, these are ~30lbs each instead of the factory 65lbs. They still recline and slide, so they are serviceable as DD seats. This is a 70lb weight savings.
CF Hood saves about 20lbs...
The CF trunk lid is maybe 8-12lbs lighter
The sunroof delete is best done by doing the E92 M3 carbon fiber roof. This saves about 50lbs, and out of the roof is the best place.
60+40+54+32 +70+ 20 + 12 + 50 = 338lbs.
If the car started out at 3530lbs (E92 Coupe) then that would bring you to 3192 lbs.