RENNtech Stainless Steel Muffler for 231 - SL 550 bmw-3-series--e90-e91---2005-2012--335i-3-0-l-i6-twin-turbo--n54-n55--esr9908178 User can load their custom

User can load their custom setting onto the HSM to set the vehicle to their preffered ride height

and better sound

RENNtech ECU HHT (HandHeldTuner) for the 209 - CLK 550

ECU Upgrade: Our proprietary tuning module stores both the RENNtech tuned file and your vehicles stock file

Front: Style: Sport I Size: 20" x 8

RENNtech Stainless Steel Muffler for 231 - SL 550 bmw-3-series--e90-e91---2005-2012--335i-3-0-l-i6-twin-turbo--n54-n55--esr9908178 User can load their customRENNtech Stainless Steel Sport Muffler for 231 SL 550. Gaines: +15HP & 20TQ RENNtech stainless steel (SS) sport mufflers are hand made and rigorously tested to remove any unwanted resonances in the cabin to deliver a deep sound that keeps with the character of a luxury performance vehicle. Our mufflers offer incredible sound in a lighter than the stock weight exhaust with improved performance. This is accomplished by reducing exhaust system back