There is an i-drive DVD player that is exclusively for the nav system in the center console. See 1st photo with red arrows pointing to "DVD" and the eject button. And there is a separate DVD changer (formerly CD changer) in the glovebox. See 2nd photo. Now my speculation is that the glovebox DVD changer outputs to the nav display and not the rear console screen. Assuming that statement is correct, I think the guy's original question was can that glovebox changer output to an Invision headrest setup instead of the nav screen, or perhaps in addition to the nav screen. Interesting question.

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