I'm not sure this meets your requirements for moving in a vehicle, because I'm pretty much a novice in TV connectivity myself. But this was recommended by some posters as an easy way to get an S6 Edge+ mirrored on a TV with an HDMI port. Sound goes to the TV, and gets muted on the phone:
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Actiontec ScreenBeam Mini 2 - plugs into HDMI port, plus it needs USB power, which I get from my TV's USB port, using the included USB extension cord.
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ScreenBeam Utility app - allows you to update the Mini 2's firmware, and also make config changes (I changed nothing, just used the defaults).
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Miracast Widget & Shortcut - Use this to connect quickly. For some reason, I could not connect after the first time using the standard way (Swipe down --> down arrow on upper right --> EDIT upper right just to the left of up arrow --> Smart View). So now I always use this widget to connect, making for just a few steps (Switch TV input to that HDMI port, power the Mini 2, TV screen says "ready to connect" or similar, then I tap this widget et voila, a mirrored phone, which plays video flawlessly in my few tests.
Unfortunately, I don't recall whether I initially connected using Samsung's Quick Connect or not. I've only used this setup a couple of times at a beach house, and I'm not there now to test and learn better how it all works (Quick Connect vs. EDIT/Smart View vs. Miracast widget).