OBD2 and Android Rearview Mirror

Hello everyone.

My new 2016 prius is on it's way, and meanwhile I'm already thinking in how to get (even) more information from it. So I would like to ask you all if you have tried something like this that I want to do.

I've been thinking about installing an aftermarket rear view mirror display with car dvr, bluetooth and android like this ones: rear view mirror android 4.4 | eBay

My idea is to use it as a gps when I need it using waze, google maps, or whatever I want, but mainly I want to have it always running Torque, Carista or any similar app to keep it always connected to the ecu using Bluetooth, so I can recall extra parameter screens with a swype of a finger in the rear view mirror, like ice rpm, temperature, mg2 rpm, and so on... and even to program alarms in case I want it, for example if the ice overheats or if I'm overspeeding.

As the Prius doesn't have many of this gauges, I think it could be really useful.

Anyone has tried them? Is the bt connection reliable enough, or just a new headache? Any suggestions on mirrors/apps? Any other ideas?