I think the problem lies in the convex shape of the dash. It curves out away from the base of the windshield so at the middle where the screen is placed the dash is also the deepest.

The Japanese seem to have a pretty good handle on where to put their in-dash LCD screens and Mercedes seems to have it figured out as well (aside from their needlessly clunky interface). Why BMW has to take up all the extra real estate makes no sense to me.