I’m pretty sure I covered all this in an old thread from a year or two ago, but here it is in a nutshell:
The RES as it comes from Ford is poorly implemented.
There are really nice ones out there, and Ford could have looked to any of those examples (QX80). But they cheaped out.
The major complaints: no ability to control from the front seats, and no hard-wired audio input to the vehicles surround sound. The Bluetooth interface is laughable—even assuming you can get the audio delay set correctly.
There are solutions—some more complex, and some more costly, but if you intend to use the system for whole family enjoyment you may want to explore them.
One solution (that I went with) was to install a module from Naviks that allows an HDMI input directly to the car‘s audio system, and front screen if the front passenger wishes to watch also.
What this looks like is a pluggable module that you install inside the center console (center stack and console must come out) and route the HDMI receptacle wherever you want. I ran my cable to the inside of the cavernous armrest bin. Once this module is installed, you install a small USB thumbdrive (formatted—but nothing on it.) into one of the USB ports in the center console and select that USB input for audio. This is just a way to tell the car to pull audio from the HDMI input, since there is no HDMI option to select from Ford’s menu Then depress and hold the left thumb pad on the steering wheel for 2 seconds and magically anything plugged into that HDMI port plays through the car’s audio system, and is displayed on the center console screen.
Perfect right? Well, no, you’re not quite done yet. That gives you glorious surround sound TV up front—but what about the rear screens?
Well, turns out the rear screens also have an HDMI input. So I installed an HDMI splitter in the center console bin also, and my “source” (which is sometimes a BluRay player, and most times my Roku streaming stick) just sends TV to front and back simultaneously. And yes that requires running a HDMI cable (DON’T BUY A CHEAP ONE!!) from inside the console bin, under the carpet and up through the driver’s seat to the headrest screen.
A weekend of work to be sure once you get all the pieces parts and panel tools you need, but the result is how it should have come from the factory. HDMI video and audio from streaming TV or BluRay on all three screens simultaneously with seamless, effortless, HD surround sound. Still not a perfect solution, but it at least makes it useable. And to toggle the front screen back and forth from “TV” mode to Ford Sync mode, just hit the left arrow on the left D-pad again.