I just purchased a 09 Denali and I hate the Nav. I saw where Kenwood has the Garmin Nav but I am worried about this head system connecting with the rest of the truck. How many different items will I have to purchase to have my rear camera, steering wheel controls, DVD, Back DVD, Sirius and probably a few things I'm forgetting to work like factory. Is there a wiring harness to directly hook up so it will work with the Bose system? Is there a better system out there I need to look at first? I really want a good Nav. Thanks for any input.