The first thing you need to know is that you are going to need schematics for both radio's, because as youve noticed the connectors arent even close to the same, they dont even have the same number of wires in each connector between the years, and if you purchased 07 connectors from the GM parts dept they are going to come with all the same color wires so they will be of np help(all the wires will be white or light grey.
) It doesnt matter if youve got the VIN from the car the radio came from, you need to have a dealer (or someone with an up to date Tech2) unlock the 07 radio. Once you install the radio in your 05 car its gonna lock. It is unlocked with the scan tool
Maven added 5 Minutes and 25 Seconds later...
Is your satellite radio the factory installed XM or do you have an aftermarket setup?
if its aftermarket, yes youll get a better sound quality if you use the AUX input instead of an FM modulator. If its the factory stuff, its already hardwired and is almost the best Sat sound you can get already