I bumped the bass all the way up, and it's better. I know that's not the answer, but it may help someone. Wish we had the Fender system in the Premium package, but I can live with it.
Anyone know where to locate the amplifier for the factory radio? I have a SEL and need just a little more "kick", so I am wanting to add an amplified sub. However I need to locate the amp to do so. I have almost taken all panels apart to locate it. Maybe I'm blind.
I am also installing a powered sub. Did connecting to the wires behind the glove box unit work? If so what color cables did you use.Found it! I continued my search and decided to follow wires from the radio media display. The CD player that is located in the glove box is also the Head Unit! A set of Euro Radio Removal tools (or makeshift) will get it to release and expose all the wires. I did a blind test with a external speaker to located front/rear and right and left. The only question remaining is which is + and - from the pairs.