Rich, don't the apple TV's require line of sight for a remote to control them ? I'm not sure if they have a provision for an external IR sensor, which you would need otherwise the Apple TV would have to be visible at all times for the remote to work. With my DVICO unit (see the other thread on the MFD2), I just installed it under the driver seat (tons of space), and as the DVICO unit had a socket for an external IR sensor, I just installed a tiny one under the dash (hardly noticeable), and ran the wire back to the DVICO plug in harness.
Because all connections (power, audio, Video and Remote) all came back to an external harness that then just plugged into the Dvico with a single socket connector, it made taking the unit in and out of the car a breeze (less then 5 seconds).
If you can sort the logistics out Rich, then I say go for it, and be the first one I know of with this setup