Coil springs support the weight of the vehicle and allow the body to move up and down. Shocks control the springs’ oscillations. A coil over combines both functions in one component that also allows adjustments to tune the suspension. Although coil overs look like struts, and can be used to replace them on many applications, they should not be referred to as struts because coil overs can also replace shocks, which are not structural suspension members. Get yourself new suspension parts here for your E63/64 (2005-2010) BMW here at Trinity Autosport.