Yeah the sound difference is going to be there with just the muffler, but it will def sound different with a full catback and the performance will quite different as well especially if you have a turbo'd vehicle.
Part number for the catback kit (535i) is 16553.

 

Oh yeah also, if anyone is interested in the Magnaflow catback for 535i for $713.25 free shipping included let me know. I'll message the vendor and see if he still has any in stock since I still have his info in my inbox.

 

Yea I'd be interested in that. Have you seen any sound clips?

 

https://www.youtube.com/watch?v=9-9C7aYjSDA
theres a video but he has other mods also on his 535i.

 

sorry about the link was on my iphone