So a friend of mine took delivery of his brand new M4 last week. He did not have it but a few days before the mod'ing has begun!
He had a friend, he goes by the name:
New Fiftyninefifty on FB: cut open the factory resonators and welded in, a straight pipe - bypassing the factory resonator - but maintaining a factory "look"! It's a pretty stealth look.
IF anyone lives in Germany and wants to have this relatively cheap mod done... just send me a PM and I will get you in touch with the welder(Nurnberg area) guru.
The car's exhaust flaps are also controlled via a switch in the drivers cockpit. Now you can have the exhaust flaps bypass the muffler when NOT in Sport or Sport+ modes.
videos after mid pipe delete... keep in mind the exhaust has zero miles on it and will surely change tone(deeper) once the exhaust carbons up some more...
Flaps open vs. flaps closed...