Check this out !
I've done this by myself for the price of 10 euro's ( 8 USD ) and 1 day
of work ,it's now 3 months ago and it sounds each day even better(0 drone )
Exhaust opened on top ,and replaced only the large perforated pipes by
full stainless steel pipe with 2,5 inch(63,5 mm) diameter,and put the
glass wool back in.
Now my ///M3 comes to live...and sounds....amazing !!!
I've already posted this pictures,and here they are again.
Do this....and do it now.....believe me guys.
And what do you think about this ???