I have been looking to purchase either the GMC Acadia soon and have noticed in the Acadia literature the radio head unit with a DVD-Audio/Video logo on it. Does this mean it will play DVD-Audio discs? I have a collection of these discs and would be thrilled to play them in the Acadia. I have also noticed this logo when upgrading to the Nav system. I personally do not want to get the Nav system but am interested in the DVD system which I believe will upgrade the head unit with these capabilities. Am I correct with this assumption? Can anyone help with this before I visit my dealer?