Will any aftermarket exhaust system for the R56 fit the 09 Factory JCW?

Thanks

 

The JCW already has the aftermarket exhaust. That's part of the JCW package. If you wanted to change it I doubt if one made for the R56 would work.

 

agreed, the JCW factory exhaust is much better than the MCS, not only is it more open, it only has the single cat in the downpipe.
I believe the Alta turboback would fit, but it would add a second cat & the giant resonator in the catback portion makes for horrible fitment and ground clearance issues. I'm constantly hearing it scrape going into our parking garage & others have had to cut the undercar brace to clearance it.