| Pretty straight forward when I did mine. If you have the deluxe interior, its just a matter of tapping into the VSS wire (green with white tracer) by drivers foot well, ordering the proper plug and terminal from gm for the green with white tracer wire to go into, also order nav antenna. Once you have all this installed, install factory nav deck where your old one was and have gm program it for your VIN. Depending where you get the deck, it might be "open" and not needing to be programmed. | 
My plan is to buy and install
Linear Mode
