Hey, i just took my '07 SILVERADO LT1 NBS to the dealership to unlock the navigation system, and i took the instructions (for unlocking it) that shawnvw posted a while ago, and to my surprise they called my and told me that the unlock was a success thanks to those instructions!!! first i took the truck to the dealer where i got it from, and they said that gm would not release the code to unlock it, what a frustration cause i got the navigation system from a guy on craigslist!
so i decided to do some research and thats how i found this forum, so thanks shawnvw and all those experts that keep us informed.
my truck came with the ugly looking single cd radio that i hated ever since i got the truck! (and as far as i know i don't have the bose system) so when i saw this navigation system on cl i didn't hesitate one sec on buying it, i didn't buy any wire harness or any thing i just unplug the stock radio and plug the navi system since is OEM to make sure it worked, (before i spent any more money in it ) but how sad i was when the "theft lock" activated appeared on the screen!
so anyway i'm going to start buying the gps antenna, the back up camera, etc etc. to enjoy this beauty, so far the radio works fine, xm and cd, it even changes the screen when i put the truck in reverse but no image of course.
the only thing that i noticed different is that the turn signal is louder but nothing to worry about since i only tap it and it blinks 3x
(i don't usually turn it on while i'm at a red light) the chime is just the same, another thing is that sometimes the screen on the navigation unit takes a little while to actually know that is day time and the screen is dim like is supposed to be at night, but it changes to day setting and it so nice and bright so nothing to worry about, besides it only happens sometimes.
so good luck to all of you who are trying to do the same swap !!!

 

ok it's been a while since I installed my navigation and so far so good,
you know I installed the back up camera a long time ago and no problem with it at all,
also like I mentioned I was having an issue with the screen being to dark in the middle of the day with the sunlight hitting the light sensor!!! so what I did was I cheated the light sensor making it think is daytime all the time!!! and that is working like a champ!!!!
see you later !!!!!!!!!!!!!!!!!!!!!!!!!!!