Thanks to this thread, I updated my 2007 GMC Sierra SLE to now include Homelink garage door openers, Steering wheel radio controls, and DIC buttons and all the features that come with them..
I bought all the parts used off ebay for must less than $200 so everything was just remove and replace, no messing with swapping items, cutting plastics, or splicing wires. I'm so glad I didn't wait to located a puller for the steering wheel. It is way easy to pull off, almost smacked myself in the chin with it. All three items only took a about 45 minutes (again thanks to reading this thread).
Has anyone tried to upgrade their HVAC controls from manual to temp sensing automatic? I know they save money by using universal harnesses when feasible, but I'm thinking the temp sensors are worth enough to omit. Not sure where they are located, but it wouldn't surprise me if the necessary wiring exists. Might be part of the CAN bus.
Next on my list is GPS, BLuetooth, and Backup Camera. Going with one of these:
http://www.adcmobile.com/cs-gm1210-ca/
Also looking for a way to add a small sub to a standard cab if anyone has ideas?