Update on the X-pipe noise

[MrLabGuy]

Took the X5 in to two additional exhaust shops one of which did custom installs to ask about the raspy sound that sounded like marbles in the pipes at higher RPM's. Seems like it was installed correctly with no leaks and the sound especially when cold is an echo which is muted by the factory resonator. I can't explain why others with the V8 don't hear this but open your door and rev the engine while cold and you can't mistake the sound.

It almost sounds like bad catalytic converters but mine were inspected and are fine with only 40K on them. Anyway...I'm pretty disappointed with the sound especially now that I'm stuck with the rattle. I guess I should have trusted the BMW engineers who decided the resonator was needed.

Michael