Originally Posted by bnekic
^ Because it doesn't offer much performance for the price and the sound is not that different.
Cat-back is the best bang for your buck.
I agree that cat-back is the way to go, but, what are you supposed to do if you want to maintain your warranty? I was going to go with a Magnaflow setup, but after talking to the dealership, they said that changing parts or modifying with non-BMW parts would void the warranty. So if I want to have anything done I'll have to use "M-Sport" parts, or, wait until the warranty is out and then do it, but that's still a long ways off.