I found a 2008 OEM sub on ebay for cheap. Took a gamble and took apart the rear panel and found that the wires are there for the sub hookup, I tested it for voltage and its all good. But, when I hooked up the sub no sound?? I downloaded the FSM for a 2008 and it says to press the "AUDIO", "AUX", and "TUNE DOWN" switches simultaneously and the current EQ Setting will be displayed. Nothing pops up on the screen? I know it may be a difference with the 2008-2010 head unit models. On the back on the OEM head unit it says Clarion. I would imagine 2008 models were made by Rockford? But also the signal wires for the sub are hooked up to the OEM head unit. So my guess it has to do with a setting on the head unit. Anyone else that can give me feedback will be appreciated. Thanks!