Since I've discovered a few things since my original post, I thought I,d start a fresh thread.
In my 2017 Ram SLT, there is installed a 10.4" Tesla-style Head unit with 1024X768 screen resolution. It looks for all the world like some of the PhoenixAndroidRadios units out there.
The top icon row is:
Navigation Radio Music Console Bluetooth Video AUX
After some time, I accidentally discovered that by swiping this to the left, more icons appeared:
Explorer Phone Link Settings App list DVR File manager Camera
Within Settings | About, I discovered this:
Model number RKPX3 (px3 manufactured by Rockchip) Android version 7.1.1
Nowhere did I see a name of the maker of the Head unit itself. It was obtained via eBay and I have been unsuccessful contacting to the vendor (Funnyhill-Auto). What was left as "documentation" ("Product Guide") is scant, poor English and grammar, etc. and basically useless as a guide. Almost inscrutable ...
Some of the basic touch-screen controls I've figured out empirically but wish I had more/better information.
* Since the layout of this Head unit is virtually the same as any I've seen, I wonder if anyone might have a meaningful guide for a Head unit like this, even though not made by the same party. Linkswell makes a great unit but it's configured differently so its guide isn't very useful. Maybe Phoenix produces a fairly generic guide that would help.
* As a curiosity question, I wonder what are the key differences between Phone Link and Bluetooth, especially regarding mobile phone use. I get that Phone Link requires that the mobile phone be plugged into a USB port that the Head unit "sees", whereas via Bluetooth, it's entirely wireless. But other than that, what's the difference?? One preferable over the other ??