The anycast didn't work so well (rear screen was monochromatic). Here's what did work, the Mirabox 5G Car Wifi Mirrorlink Box A/V + HDMI (Mirroring for Phone). I got a used one on eBay for $10, but new it's like $100. It's pretty cool, with av output switch (you can keep your playstation player a/v plugged in and switch between sources. It has hdmi out. It can get power from a micro usb or 12volt. Your phone connects via wifi (screen mirror) or directly by plugging in, which also charges the phone. You can expand youtube videos to play full screen on the front and rear screen. The phone itself prevents you from screensharing things like Netflix or your TV provider, so streaming movies isn't possible. That's more of an iphone legal thing than a technology thing. I've got the VIM option so that is possible as well. On both wireless and cirect usb cable, there was some audio feedback, but it was not entirely annoying and could just be my vehicle.
What did you end up going with?