BILSTEIN B3. COIL SPRINGS IN A CLASS OF ITS OWN. The best option when a replacement is needed. In the event of material fatigue or an accident, you can rely on proven BILSTEIN quality for your repair, perfectly matched to the shock absorber. Perfectly matched for every vehicle. As a successful original equipment supplier to the world's leading vehicle manufacturers, we know exactly what you expect: uncompromising quality. is for the world's leading vehicle manufacturers, we know exactly what you expect: uncompromising quality. This expectation is met by our BILSTEIN B3 line of OE Replacement Coil Springs.