An M car always has more presence.
With a 6er GC, it is like this : a 5er is always nice. Lose two door, make it wider and lower and it becomes a 6er coupe which is nicer as it is sportier but more impractical, but you live with it because of the looks. But when you add two more doors to it it becomes a 4-door which is impractical and now even longer, but it is cramped inside. So when you drive it and park it, but then you get into a 5er, it suddenly comes upon you that you should have gone with a 5er in the first place and save the extra cash for a nicer set of wheels etc.
And the more and more people realizing it, the fewer and fewer sales it has in the real world (at dealers)