I've tried several times unsuccessfully to remove the radio head unit on my 2013 C250. I have removed the AC vent cover plus the two T20 screws on the top of the radio head. However, at this point the unit will not slip out of the opening.

I did find a European YouTube video showing the procedure for removing the head unit from a facelift W204. The last step is to put the key in the ignition, turn to the second position, move the shifter to D, then turn the key back and remove from the ignition. At this point in the head unit can then be extracted. The problem with this is that with the automatic you cannot remove the key from the ignition with the shifter in the D position. You have to place the shifter in park before the key can be removed. I've tried various combinations of the shifter position and the key but still cannot release the head unit.

Anyone know the secret?

 

Found it! Just didn't search far enough. After partially removing the two T20 screws, push down to release the head unit.