Sup all! I have been approached by a few friends about putting a moderate system in their 2007 gmc sierra classics. THere have been some horror stories about once you take the factory HU out, the whole truck siezes up. I have done a few 06's which need a peripheral to get, say, the door chimes and other piddly crap to still work after factory HU removal. Question is "is there anyone out there that has any helpful information about RR gmc factory HU's?