E46 M3 Convertible A coil spring’s job is to hold the weight of the car up, while absorbing impact from road surfaces. Coil springs have been used to suspend automobiles as early as 1906 and are found in nearly every modern production car. Vehicle sagging, uneven tire wear, excessive noise, bounce, or sway can all be symptoms of sagging or broken coil springs. When replacing coil springs it is highly recommended that the parts be replaced in pairs. It may also be the right time to replace related suspension parts such as shocks, struts, bushings and strut mounts. We offer a wide range of pre assembled strut/coil spring assemblies to make this job as easy and effective as possible.