Great choice! I am running one with my Dinan muffler and LOVE it... Very noticeable difference and no pesky CEL lights, etc... They rarely come up used for sale and when they do, they are gone in less than one day. I have only seen 2 in the past year IIRC.
2008 E90 M3 | Interlagos Blue | Speed Cloth | 6MT - A work in progress...
2011 E92 M3 ZCP - Gone, but not forgotten.