Can an MP3 players built in EQ setting dramatically improve the sound out of the factory nav sound system? The reason why I ask is because I am suffering with some TERRIBLE sound out of my new cars sound system. I was trying to get my mp3 player to work with my nav unit via the usb connection. This didn't work so I tried the aux input, voila! Sound! And I immediately noticed a marked improvement over the sound coming out of my speakers. So my question is, can I achieve a better sound quality using the EQ on my MP3 player vs the OEM headunit? I know this must sound like a stupid question, but I am almost in disbelief right now.