Say I wanted to add the steering wheel stereo controls to an 06... is it simply a matter of buying a new steering wheel or are there miles of wires to be run (IE is the harness for this already in the truck).

 

The wiring was not there on earlier models, so I suspect it would have to be added. Clockspring also has to be added or changed out. It's not an easy job, not a cheap job, but it probably can be done. Others have done it on '04s I know. Don't know if the computer bus is an issue on the '05s and '06s or not.