I got the double adjustable TC Kline suspension, it's great on the track, but watch out when going over a dip in the road, the suspension drops fast and hard with a big "clunk". My wife won't ride with me in the car anymore!
2008 BMW 135i coupe w/Sport Package, aFe cold air, TC Kline double adjustable suspension. AA Charge pipe with BOV, AA cat-less Downpipes, and AA larger FMIC. SuperSprint section 2 mid-pipe, Cobb access port, and Corsa axle-back exhaust.