I expected what would be the initial reaction, until someone actually simply understands what needs to do in order to replicate this and hear it for himself.
First of all, I always drive with windows down both mine and passenger side, so that's how I spotted this difference way easier.
Now, yesterday I wanted to find out if exhaust clamp opens like it does in Sport+ mode, but it doesn't.
I instructed my friend to switch between the modes, while I was listening at the exhaust side, and it opens on idle just in Sport,sport+ and DSC completely off(press DSC for a long time) mode.
While, I couldn't hear clearly, but when in comfort mode + DSC button pressed once quickly, exhaust clamp is closed on idle but I think it open up over 2k RPM's.
Which clearly makes it exhaust dynamic mode which is not mentioned anywhere in the manual.
This is why I think it's a clearly "easter egg" thing, as it doesn't have any actual purpose except to draw a lot attention while commuting in town with normal gas response.
Anyway, huge thanks goes to sneaky M engineers who implemented this without telling their superiors about it and making it official.
After finding about it, I simply lost need to go MPE, so I will stick with stock exhaust muffler and get fabsport sport-cat for sure! I think it would be the brutal combination.
