Im looking into buying a deck for my car and am close settleing for an alpine 9847 i believe. My plans were to run and AUX to the ipod instead of buying the k420i(if thats the right model number) interface. I normally listen to my songs in shuffle and haven't really setup playlists and what not. Does the limitations on the K420i affect if your just listening to your songs in shuffle mode? Is there a sound quality difference between the k420i vs running an aux to the bottem of the ipod?