Step 1. = Yes. the rear speakers will turn off and headphones are on, playing the DVD.
After Step 2. what ever input I select the headphones and rear monitor changes as well.
Before doing step 1, did you turn your DVD on by pressing the button on the steering wheel? You must use it first to turn the DVD on. If you just selected the DVD from the panel, it will control both the front and the rear.
Try that and let us know!
2004 Nissan Armada LE
Minneapolis, MN, USA.