I kept searching and found a post titled "8200NEX Won't mirror to rear screen". I guess the answer is that the mirror function doesn't work either. Seems kind of odd. The NEX line is suppose to be a top of the line AV radio. No one buys DVDs any more, but even then, that function only works when the emergency break is on. Not much help if you use your vehicle to, say, go places. I guess the use case is that you can watch a DVD while sitting the Walmart parking lot. That's useful how!?
Apple airplay doesn't work at all since the HU isn't an apple device, and apple devices don't support miracast.
If the post quoted above states the truth, the mirror function doesn't work, period, for anything even though you can select it as a source for the rear screen. If true, it's not clear what the issue would be with displaying the HD radio album art, or the GPS map screen. Is it really true the Rear/Mirror function does nothing?
The 8400 has HDMI input, but like DVDs, wont work unless in park or you do a work around. And, even if you do overcome the parking brake issue, HDMI has the additional limitation that it wont play on non-secure devices like a rear screen unless you do another workaround and downgrade the digital HDMI signal to an analog RCA signal. Today, most of my content is on Vudu, Youtube, Amazon. It's all legal. It kind of sucks the only way to make it work is to use an HDMI cable to back convert the digital signal to RCA. I guess the other option is to rip the content to an SD card, but that's a lot of work and forces something questionable conduct which is unnecessary when I have legal access to my content on the internet. Is this the state of things?
It looks like there are discussions of jailbreaking the software. Are there any better options to make these HUs work as promised? My goal is to be able to play my clouded content on the rear screen, while moving, to keep the kids entertained. Hell I would be 80% happy with a youtube CarPlay app that lets me play me and my friends homegrown videos.