SPL Parts Rear Lower Trailing Arms — BMW E8X / E9X

Replaces the flimsy stamped steel BMW arms with billet units, improving rear suspension rigidity and reducing weight.

Why It Matters

Rigidity is commonly overlooked but critical. Under hard acceleration and braking the arm sees hundreds of pounds of force, causing the OEM arm to deflect several millimetres. Combined with OEM rubber bushing deflection, this produces instability from rear bump steer — and bent OEM arms are a known outcome.

Fits BMW E9X 3-Series and E8X 1-Series, including M models. Made in the USA.