A friend with a bypassed Z1 showed me how he can watch movies in the backseat headrest monitors, but still have the map on the front screen, or listen to different audio.

I have a bypassed Z2, and I can't find any setting that lets you watch & listen to a movie in the back seat, while listening to music and watching the map in the front seat. Is this a capability that the Z2 lacks? If so I will be seriously bummed -- I need to be able to navigate while my kids are watching a movie.

Look on the A/V source screen on the right hand side, second row down. There is a buton that allows you to change the rear output. It toggles between DVD, Aux, and Mirror.

Yah, as long as your kids want the DVD and you don't want "aux" with video input, you can do this without the avic bypassed.... it is what it was meant to do.

OK I found the Source option to send the desired video to the back seat.

But is it possible for the front seat passengers to listen to music, while the back seat passengers watch the DVD and listen with headphones?

Yes

OK I found the Source option to send the desired video to the back seat.

 

But is it possible for the front seat passengers to listen to music, while the back seat passengers watch the DVD and listen with headphones?

I believe you would need to run the rear audio outputs which are on the back of the z1 to the back seat and then to a splitter for 2 headphones. They are RCA cables (A/V) that come out of the back of your z1/z2. Took me a while to find this as well, was pissing me off.