I had a 6 disc radio with rear seat entertainment (Rear dvd). Everything worked fine. I just purchased a nav radio from another member and took it in to the dealer to get it unlocked. Everything now works great except the rear DVD. I don't have that input to select anymore. The DVD player works fine, but I have no audio through the radio and I don't have the headphones that came with it. Is there something that needs to get turned on with the tech2 or something? Thanks