Koni Single Adjustable Rear Shocks - Preadjusted to match rear spring rates using our shock dyno. The street/touring is now exclusively the ";top-adjust"; version, which adjusts from inside the trunk with no tools needed. The rear shocks are custom built and valved by Koni to GC specifications, and are shorter than standard Konis.

Eibach Springs - All popular street spring rates are available. Ground Control springs are made by Eibach on German machines both in the USA and in Germany, however all Eibach springs have a lifetime guarantee against sagging, rate change, or any manufacturing or material failure. Lifetime guarantee. Compare!

Ground Control Bump Stops - We do not just ask you to reuse your stock bump. The stock bump stop is designed for stock suspension; we provide a bump stop designed to work with our suspension. These are soft foam, same quality as OEM BMW parts, but made to our specs in Germany. Our race bump stops are even different than our street bump stops.

Ground Control Rear Ride Height Adjustment Kit - Billet aluminum threaded adjusters bolt on top of the rear control arm. The E46 M has a larger diameter rear axle than the standard Z4, so it is necessary for clearance to not have any portion of the adjuster below the control arm.

Ground Control Racing Camber/Caster Plates - More camber adjustment than stock, caster adjustment, aircraft bearing, engraved with calibrated degrees, with stainless steel reinforcement. Every component is anodized or plated, including fasteners. Adds extra travel to avoid excessive bottoming out, this is a very well engineered product. The stainless steel reinforcement prevents electrolysis between the steel fender and the aluminum camber plate.
Camber is quickly adjustable by sliding the mounts, without removing any components from the car. The priority of this design is to allow fast, repeatable alignment changes at the track. Caster is adjustable, when necessary to correct the car, by changing a shim under the plate.
The Ground Control camber plates feature a urethane bushing that carries the side loads only, and does not rotate (no squeek!) and allows for articulation of the shock shaft. This urethane bushing is very under stressed, as the Ground Control design does NOT support the weight of the car on the urethane bushing. Instead, the weight of the car is supported by a completely separate rotating ball bearing, which is also manufactured in Germany. The entire assembly is machined at an angle, just like the stock upper mount. Beware of less expensive machining that bends the strut shaft after installation.