can I replace my 06 factory stereo for an 08 factory stereo?

An 08 radio with the Aux will work just fine in your car.
It fits perfectly. You will need the dealership to marry it to your car
via their Tech2 (laptop). It takes only a few minutes to do.

I know this for a fact becuase I did it. I have an 08 Monsoon radio in my 2005 G6 GT.

2007 didnt have the aux so look for an 08. I have pix if you need them.
Robert

Do the install youself. I can even show you a "how to".

It still needs to be married to your car via a Tech2 at a dealer but you can physically install the radio yourself. clicky here

Also shop dealerships cause they all charge differently for this. It might ork without it. Mine did.
But it wouldnt show monsoon at startup so I got worried and had it done. Now it does.

They charged me $80 to program mine.
Then found out another dealership would have done it for $60. aarrggggggg

So shop around.

Ask em how much for 1/2 hour of Tech2 time?
Thats all it takes.....

Hood release cable??? I didnt have to mess with that! lol

They go here on the Tech2.
I am not a Tech so I cant give you the play by play but its:

Radio Setup
To setup a new radio for the vehicle, complete the Module Replacement/Setup procedure under the Radio menu of the scan tool.
Cycle ignition when complete.

Click to expand...

That is why you do it....to get the aux!!! That and most peoples cd changers crap out in less than 3 years. Just get the 08 single CD so u dont have to worry about that anymore.

AUX FTW!!