Finally finished mine. Got the JDM bracket and the JDM hazard switch. I set it up a couple months ago with a Pioneer AVH-1550NEX and a Sirius receiver. I've had it running with the Hazard Switch hanging out because I misplaced my Dremel. Works pretty well, especially the CarPlay functionality. I also have that dim display on the HVAC that was all over the other thread. I haven't tried that brightness button trick, though.
Cut to today, I found my Dremel and got to work. I ran the USB line to the storage bin and cut a passthrough hole for it, so the cable's in the place I wanted. I also had to cut a lot out for the Hazard Switch, but in the end, it's pretty decent.
My only real complaint is that the lower bezel of the Pioneer is angled so that it catches sunlight and directs it into my eyes when I'm driving. It's a bit annoying when I'm driving in a tree-lined area, and it tricks me into thinking that the Pioneer display is changing.
http://ackthud.net/jont/2019/Misc/Subaru-Pioneer.jpg