Originally Posted by Remonster
As far as I've read, the dome (at least in the case of the E9x M3) was to help cool the V8. I think it would fit without it, but it would overheat without the room above it for air to flow over. I doubt a six cylinder turbo would need a power dome, look at the F10 M5 which has no power dome.
Previous M5 didn't have a dome either.
To me...it's less about functionality and more about what visually separates it from the base 3. You take a quick glance...see side vents...M. Quad pipes...M. I see powerdome...M. Flared fenders...M.
The side vents weren't funtional on the E9X either...but I'd wager they stay for the same reason. Not to mention...a lot of styling is the way it is on vehicles because...it looks good. The dome looks good imo.