My butt dyno tells me I can feel a difference at about ~250-300 lbs weight savings (car only feels slower with 2 more people in it)
Bang for the buck, the most cost effective way I can think of to shed weight, while maintaining a full interior, is to replace the following:
Forged Rims (~25 UNSPRUNG lbs depending on brand)
Seats (~60 lbs)
Exhaust & DP (~40 lbs)
Battery (~30 lbs)
Self Diet (~10 lbs)
I think that would get me right around 250 ish.
With today's gas prices hovering near $5 a gallon, maybe these mods would even pay itself off after a few years
Only problem... anybody know how I could install fixed position recaros into my E92?? How would people get into the backseats?!?