smiddy 76 Report post Posted May 13, 2009 Stainless 304 polished or ceramic coated. Suit M50/52/54 with mid cats. Big gain in throttle response and fuel saving, 7rwhp gain on my stock 328. Bolt direct to OEM front pipe. Polished = $450 to Bimmer members, complete with gaskets and bolts. Quote Share this post Link to post Share on other sites