according to the part number..65129289971....it appears that it is not on the gran coupe M6...unless I may be missing something? I can't remember where I read it but this is consistent with what I read on the m6 gran coupe...the m6 coupe on the other hand may have it.
I already think the exhaust note on the M6 gran coupe is understated as it is...it would be a real disappointment if it was amplified as well...then without it, it would be really crappy.
http://parts.bmwmonterey.com/a/BMW__...n/65_2365.html