After my K-sport coilover are dead after 60k, I thought I build my own coilover with Koni struts. No, it wasn't cheap, parts added up to be over $900, plus my labor of putting it together. But I have no more rubber spring seats.
$60 Afco Adj. nut lower seat - AFCO20133
http://www.speedwaymotors.com/AFCO-...el-19-23-24-25-Series-Adjuster-Nut,40551.html
$60 Afco 5" coilover sleeve - AFCO20134
http://www.speedwaymotors.com/AFCO-...eel-19-23-24-25-Series-5-In-Sleeve,40531.html
$100 10 inch 2.5 ID springs
http://www.jegs.com/i/Aldan-American-Shocks/038/10-220BK/10002/-1
$24 Upper Strut Bearing
https://www.ecstuning.com/b-genuine-bmw-parts/upper-strut-bearing/31331090612/
$50 spring joiner
https://www.ecstuning.com/b-h-and-r-parts/inside-spring-joiner-60mm-priced-each/ztix002a01/
$26 Spring top from
https://technotoytuning.com/universal/parts/conical-upper-hats-coilovers-25-id-springs-22mm-center
$23 EMPI 86-2199D CV Boot Kit to cover front struts
http://www.ebay.com/itm/172464392159?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
$10 Washers from Aces Hardware.
$22 Spacer from eBay
http://www.ebay.com/itm/121425060226?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
$135 shipped Camber Plates from eBay
http://www.ebay.com/itm/141005441757?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
$400
http://www.ebay.com/itm/Koni-8710-1...ash=item48969f335b:g:FcMAAOSw44BYWnwu&vxp=mtr