Coilover / Shock was needed is due to the spring can't stable immediately , the spring will continue for a time stretch and shrink after compressed and released, the coilover / shock could absorb the vibrations caused by wheels meet uneven road surface, become comfortable.

BMW E36 318 325 M3 3 Series Adj. 24 Damper Coilover Shock Absorber Strut Suspension Kit
- 24 Ways Adjustable Damper Coilover / Shock Absorber Suspension Kits
- Fits: BMW 3 Series 318i, 318is, 318ic, 323i, 323ic, 323is, 325i, 325is, 325ic, 328i, 328is, 328ic, M3