As far as I know,the main addition to the extended nav. includes a feature which allows you to keep track of your trip.
You can " back trace " the route you just travelled , even if the road is too small to be on the map(or not on the map for some other reason )

i.e. you may not know where you are or where you have just been, but you are definitely NOT LOST . Lol

Regarding the DVD, stick it in. It can do no harm, but the DVD player may not recognize it .
I put a regular DVD into mine( in the vain hope I may get a picture but.....)
Then I put the Nav. DVD into my computer.It shows the files on the DVD but will not let me open them.