Z4MC now sold and I had these sat in the garage just in case I needed to go back to stock. Switched to 100 cell cats in 2009 and sold the oem euro cars at the same time.
These cats are from an e46 m3 so will need a slight adjustment to the x pile so as to fit .. Its what I was going to do if the car wasn't sold with all the mods.
Price at $450 plus shipping reflects the modification you may have to do when fitting. This could be done at any custom exhaust garage. If it helps, I also have OEM x pipe that I could throw in for $200..
Cats
http://s1052.photobucket.com/albums/...ps9f844811.jpg
Oem x pipe
http://s1052.beta.photobucket.com/us...08572.jpg.html