Well, from the sound clips I heard of the M3 system it didn't sound bad at all.
But it's definitely not the same sound between the V8 and the 6 (which I never thought it would).
On the M3 it has a low tone at idle and lower RPM's - then switches over to a more Euro high pitch at upper RPM's.
By that clip it doesn't sound any different at idle than stock and is all high pitch after that...
All of the M3 clips were with cat delete & hi flow X-pipes which may also make a difference if the above clip is with cats and res
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