I've done some searching but couldn't find anything of relevance:

I found a pretty good deal on a late model JCW exhaust for my 2003 MCS. The problem of course is the fitment. Has anyone been able to make a late model exhaust fit an early production MCS?

Is it worth the trouble?

 

The fitment change should only be the difference in the 2 inner exhaust hangers. That the 2 inner hangers on 02-03s are straight to the rear, 04-06s are turned towards the battery box.

So a early exhaust should just need the inner hangers adjusted.

 

mdsbrian is correct. A friend of mine put my 2003 vintage Borla exhaust onto her 2005 MCS and just needed to take it to an exhaust shop to get the two hangers bent to adjust the fitment.