Before committing to the OE NAV Radio Option with your new truck purchase, you may want to check THIS (http://www.dieselplace.com/forum/showthread.php?t=446183) out first.

This new unit from Advent is designed to look like a OE installation, offers additional & better functionality, better NAV software (iGo Primo), and is much less expensive than the factory NAV option. It retains all factory options and functionality like steering wheel control, backup sensors, rear cam, XM radio, etc., or you may add some of these options if your truck is not originally equipped with them, Easy to install yourself too...

I ordered my truck with the backup cam, non-nav radio. The Advent unit will soon take its' place. An excellent way to go for LT's or LTZ's.

I'm not a dealer or affiliated with the product in anyway - just passing along something I hope will help some of you contemplating new truck options. This may save you money and get you more features. I'm glad I found it for my new truck.