Thank you for the update. Your GM Solutions had posted a method on the Forum for the conversion of a 2005 factory non-navigation to a factory navigation Radio/CD unit while still retaining all of the steering wheel controls, etc. I will continue to look for another shop for this work. I have searched throught all of the previous posts on the Forum on this topic and one individual (Eric Salvas) was able to wire the system together and retain all features. However, I have not been able to reach him thru the Forum.