Shop 1999 BMW 328is Coil Spring Damper. 318, 325, M5; w/M-Technic. 4WD. CONVERT NEW STYLE, w/o M3, w Springs, STYLE, Failure - OEM BMW Part # 31331133513 (31-33-1-133-513)

Absorber.
A component (mounted in the center of the spring) which cushions the spring as it is compressed. W/o M3 w/Sport. Additional shock. Bumper. Coil Spring Damper. Cushion.

Coil Spring Damper

318, 325, M5; w/M-Technic. 4WD. CONVERT NEW STYLE, w/o M3, w/Sport. Sport. W/o M3, w/Sport.
Suspension Coil Spring - Repair or Replace
Your coil springs are not especially prone to failure, but if they have been cut, clamped, or heated to have the vehicle lowered, your might benefit from replacing the strut springs. Excessive rust can make the springs more prone to failure. Contact your local service department to have your suspension system evaluated.