So never seen this b4 (my car audio xp is in much older cars) but I'm wondering if this is an issue with 2007 Pontiac Grand Prix (base sedan 4 door, no monsoon/bose) ... (can't find any details on Google)

I am trying to get use out of an older sony xplod CDX-ca810x (dated 2003) that is just collecting dust.

On the sony wiring manual it mentions if you have antenna within the back glass/rear defroster (which I do) in the hard to read notes it says connect blue antenna remote lead (or red positive) to the "power terminal of the existing antenna booster". For details contact car dealer (yeaaaa they not much help).

No, I haven't removed the factory radio yet but when I do... Do I have this "antenna booster"? location? What look like or color of the Pontiac wire?

I've looked online at Pontiac stereo wiring diagram and don't see any mention of an antenna booster (maybe i dont have it).

But I'm also reading if this booster does not have a +12v switched power then rear window antenna/defroster the FM radio signal will be weak or none at all?

So uhhh what the deuce, help?
(replacement of the Sony HU is not a option at this time, if this is your answer don't waste your time).