Looks interesting, can you mount the swivel further back, so it's not sticking out as far, or do you want a wide range of motion so you can point it at you more?
Also, it might be easier to make it look factory if you mount the acrylic behind the faceplate and build up, instead of shaping the acrylic down.
I use Tasker, configure it so when USB power is on, it starts your apps, and when the USB power is off, it closes the apps.My tablet has a full charge so I am simulating a situation where I am leaving it mounted with the screen light off and the Tunein app launched. It should hold a decent charge for a while (a work day at least) if no extra data is streaming or apps are being used. I could just close all of those things before I get out of the car but that manual process would get old after a while....although I could just use the task killer for that with just one button