I own a 2011 MB C200 (W204). It came with the fixed-screen center display. The question is simple: can I just buy a flip-out center screen (which is bigger and it as more features) and just replace the display without purchasing a new HU?
I believe the two displays have a different number of pixels too and you would need the head unit swapped too to make full use of it. If I remember right, someone tried the bigger screen, it sort of worked but only for a portion of the display area.