A quick Google search can give you more info on the install.
![gm navigation disc 2005 yukon gm navigation disc 2005 yukon](http://www.2040-cars.com/_content/cars/images/93/515093/001.jpg)
If it's a brand-new unit, you may not have that problem, but the amps do, to the best of my knowledge, still have to match up correctly. If you reinstall it in your car, and the VIN doesn't match, the unit will not work unless it is cleared by the dealer computer. You may be able to work around the Theftlock codes on older units, but the newer 6-disc and Nav radios actually learn a piece of the VIN of the car in which they are installed. Plus, most of the units for sale on eBay are Theftlock, and need to be cleared at a dealership to work. With a Denali, you are probably fine, since it uses the Lux amp setup, as does Cadillac, but with a base or Bose you may have trouble. There are (I think) three different amps: base, Bose, and the Lux amp. I believe you have to have the correct factory amp for the Nav unit to work. Hope this helps, and I'm not off base - maybe one of the dealership guys on here can give you a better breakdown of the process.