'08 gm nav dvd won't play

I'm in need of some help with this thing. The Nav appears to be DVD capable but I get a disc error when I put a dvd in. It says in the manual that the DVD feature is unavailable with out the "Rear Seat Entertainment" package. Does anyone know if this can be enabled with out the package? Or does anyone have the package, and if will it play DVDs in the Nav system or is it inputed. If i could find a spec sheet on this that would be really great. I have done some searching and have not been able to find the info I need. Here is a picture of the unit, just scroll down the page a bit.

http://www.coastaletech.com/GMLOCKPICK.htm

It's not a question of if it will work its how can I get it to work. I know there's a way. On GM's website there are two different NAVs one with Rear Seat Entertainment package and one with out, but they both have the same order code. I think it's got to be software enabled, my manual says it WILL play DVDs if you have the RSE package and that tells me there's way.

I'm willing to bet that the one with rear seat entertainment only displays on the back seat.

How much would you like to bet??  Says in the manual that it will play if it's in park.

I would beleive that, but it won't play all the time like the rear screen.

Your best bet, I would think, would be to find a vehicle specific forum and ask there.  They would know the answer right away (and it's probably already been posted 10 times).

I've personally never understand the attraction to being able to watch movies on a small car screen while the vehicle isn't moving.  I guess I just don't spend that much time in my vehicle.