I must admit, my initial thought was its blowing but after checking, all good. Sounds a little different once warmed up but loving the growl.
I've heard some people have the backbox opened up and different mods done such as wrapping a pipe or removing the insulation. If I were to do it again knowing what I know now I think I'd try that. But then again, until you've done it, you never know!
I checked out Youtube for an idea on the sounds but as Maniac says, it's hard to tell without actually listening to it for real, what it really sounds like.
In summary, I like it BUT the drone at the wrong revs can be extremely loud.
2011 Deep Sea Blue sDrive30i Z4 Highline, 19" 326 Double spoke, M sport, Cream Leather, F & R PDC, Heated Seats, pro nav and SmartTop. Previous cars: 3.0 V6 A4 Audi Quattro and Nissan 200 SX S14a touring.
