To review a vehicle such as an M5, things must be placed into perspective. It's not just 'performance, fuel economy, fun etc., but what are these things from the perspective of what this car is. The car is a high performance sedan designed and implemented to the highest standard. This vehicle must be rated high in all categories. I get 17+ mpg in town unless I'm in one of those moods and when I am in one of those moods the sheer thrill overrides all. I don't care about cup holders. If you like to drive high performance teutonic understatement this is it.
The car fits. It drives, It feeds back and won't sass.
I've never needed one, but perhaps a spare tire for security.