That looks like an excellent solution @dynamicdave.
Do you have the display permanently on, or does it wake up with a touch?
I wonder if my Tesco Hudl (Android 4.2) and Google Nexus 4 (4.4) can be rescued from the shed and persuaded to run Wall-Panel.
I've tried using them for dashboards before but when the screen goes off you have to press a tiny button (and wait an extraordinarily long time) to get it back.