Can I play movies on NAV-Radio
 

Hi all, I just picked up an 04 Yukon Denali. It doesn't have the Rear roof mounted DVD player but the NAV-Radio is DVD based. I was wondering if I can get it to play movie DVDs. I can't get it to recognize any movie DVDs but the NAV map disk is a DVD? I'm not interested in driving with a movie playing. I respect how that is a bad idea. I just want to jump in my rig during lunch and enjoy some mindless entertainment now and again.