I do not have the Nav system, but my 2010 GM Terrain has a single disc for the CD/DVD. I had 2 little ones watching a *super annoying* DVD with their headsets on, when the headsets suddenly stopped receiving signal, thus making ME listen to the movie over the regular speakers. THEN, they wanted a new movie and after pressing EJECT- I get "mechanical error" on my display. The disc won't eject. Pressed it a few times, and then it reads- please remove disc. HMMM Anyone else have this problem? I have a disc stuck in my player now. :\ TIA Jenn