This is the BiTurbo Muffler for the current model A55 engine (from 05-09). Can increase speed approximately 4-6 mph. It works great. Comes complete with gasket. Requires removal of only 4 bolts. Very easy to install . I have put it in several models. Not Legal in All states. Check you local Law. Check out our website for Laws for your state . Also available for earlier models.
