Additional DIN size unit?
 

I want to install an extra DIN sized unit in my X5 which has the standard radio with Nav etc, so the tape player (this also contains the radio electronics I believe) is behind the screen.

It's actually an Empeg MP3 player with a display on the front that shows playlists, tracks etc so it needs to be visible. But I cannot think of where it could be located. The ash tray would be a good spot, but there isn't the required depth.

Does anyone have any suggestions as to where an extra unit could be installed?