I generally use my phone on pandora or my playlists when we are on the water. (I have the stock Sony head unit with usb input). I connect the iPhone to the mini-jack port on the front.

I connected a thumb drive to the USB port cord the other day, and it sounded terrible. My subwoofer sounded blown and my cabin speakers were muffled.

I have tons of music that I could use if I could get the USB input to sound good, but these are all Mp3 songs that I do not have on iTunes.

Has anyone used the USB port with good results? If so, what was the way you used it? It would be really nice to just have a thumb drive full of music I could leave on the boat.