I don't think there is anything you can do with the Nav unit but "play" the NAV dvd. I think the boot record is part of the player. In fact so is much of the op system that seems to be stored in ROM.
For instance I upgraded to the 2.05 disk from 2.03. Later I decided to downgrade but the system still has the 2.05 program loaded even though the disk is 2.03. I have a procedure that I have to run to force the 2.03 op system and program to reload into the firmware.
That's what I thought..
But when I take out the navigation dvd, it works in my dvd player on my computer, and i can see the files on it, and was wondering if I use some of the similar files, and then burned a movie in addition, if it would work...
Well I don't think the NAV boots from the DVD but from firmware in the player. The DVD supplies the op system files to some extent for original load and just maybe some routines during runtime. Don't know for sure.
As far as movies go you would need three things the Nav does not have. A MPEG decoder to uncompress the movie files, a Dolby Digital decoder for the sound component, and a player to move about the movie.
Also you would not be able to use the nav unit while playing the movie. There are other threads here that describe how to use the indash screen to show dvd movies from another player (which in most states is highly illegal).