08 DMAX LTZ

This may have been asked before, but I cannot find an answer here, so sorry if it is a repeat. I own an 2008 HD Silverado Crew Cab LTZ with Duramax. I inatalled a Autostrata back up camera system (supposed to be exactly what the factory installs). It is all hooked up properly and I went to the dealer to have my factory Bose/NAV radio programmed to accept the camera and the tech said he could not do it because my vehicle was not an option he could select in the computer - i.e. it did not list an 2008 HD truck as an option, and that he also needed a VIC number from GM. He was concerned that if he used the Tahoe, Avalanche, or other software that it might cause issues with my vehicle otherwise. So my question is this. How are other people with my exact same truck getting their NAV units programmed, and is what the tech told me entirely accurate? I have been told the opposite by other dealers so I am confused as to how to handle getting my radio programmed properly. I read a post on another forum where a tech said he was programming trucks as commercial trucks, but I am no tech so I cannot understand what that means to a dealer. Thanks for any help.