Here's the 1st response I got from them...
Thanks for contacting us.
About your questions:
MZ3D has digital screen, it means the image is better than our MZ3A.
MZ3D have 800*480 pixels. MZ3A 480*234 pixels
You can connect headrest entertainment with our MZ3D and watch different movies in the front and the back also.
MZ3D looks more OEM than our MZ3A.
MZ3D can use sorround sound like Disco, stadium, cinema, studio.
About the navigation, we send Route 66 but you can use Sygic, Finean map, etc, all they come with voice command, it stop the music when make a turn.
Check the pictures, first one is route66, second with sygic.
I used to use Garmin but They work really great also.