Bilstein sports are not supposed to be used regular springs but short sport springs. Your springs are too soft for the sports. I have Bilstein HD on my 88 735i 5 sp and they are a great ride perfect. I live in the Washington D.C. metro area and they feel tight but the ride is smooth. My only complaint is the front of the car sets up slightly. Bilstein are a better quality shock than Boges gas shocks and they have a life time warentee(sp).