I'm just curious what the specs are of the stock amp that runs the factory subwoofer. Anyone have any idea? If it's respectable enough to run a new quality replacement 8" sub, that's what I'm going to do. Why you ask? Because I'm trying to save $$$ and up grade the sound a bit. I have the CDA-9884 Alpine head unit, SPR-17c 6.5" Alpine speakers in the 4 doors. Just want a little cleaner bass and not comprimise cargo space. yes, I'm getting old. Any help would be greatly appreciated. Yes, I've called a GM dealer and it amazes me that they can't answer my question. That info is somewhere!