Buy 2016 Subaru STI Base Coil Spring R (Rear). Suspension Coil Spring Your coil springs are not Springs, Suspension - OEM Subaru Part # 20380VA020

Coil Spring.

COIL SPRING-REAR Coil Spring

Fits STI, WRX

Suspension Coil Spring
Your coil springs are not especially prone to failure, but if they have been cut, clamped, or heated to have the vehicle lowered, your Subaru might benefit from replacing the strut springs. Excessive rust can make the springs more prone to failure. Contact your local Subaru service department to have your suspension system evaluated.