Whiteline 15-18 BMW M3 / 15-20 M4 / 16-21 M2 Front Control ArmFactory rubber bushings are intentionally soft and open in design to allow multi axis movement during steering, but under heavy braking they compress and release, allowing unwanted arm deflection. The result is reduced stability, inconsistent braking feel, and tire skipissues that are amplified when ABS is engaged or the car is driven hard. Whitelines upgraded arm and bushing solution dramatically reduces this compliance, keeping the suspension