In the suspension system, there is an important part named coil springs. Simply, a coil spring is a shock-absorbing device. It can be compressed or stretched by the vertical movement of the wheels on roads. If the road is uneven, the coil spring will be compressed. Otherwise, it will stretches to the original state. Some superior coil springs are coated with vinyl. However, there is still a time for coil springs to gets useless no matter of the material. If your car suffers overloading, fatigue or overuse greatly, there is a huge possibility that your coil springs is failing. It is easy to find the coil springs and change it by yourself. Now, you don't need to waste time looking for another good website as us, since you offer all BMW genuine OEM coil springs with the lowest price.