I did a little research on high end auxiliary cables and after filtering out alot of BS actually found something that worked. Recently bought an OFC Aux that actually cleaned up my stock audio systems sound and gave me better clarity throughout the 15-25 channel sound range. It made the stock bass alot crisper and the treble never sounded so clear. At around $10 bucks I don't see how anyone could lose. The 50 cm cable(does come in more sizes) is just long enough for the mp3 player to tuck in to the lower storage area too, getting rid of all the extra wire u get with a normal length cable.
I have my audio settings at: Bass +2, Treble +3, Fade 0, Balance 0, and have my mp3 player at about 75-80% its max volume
Here's a link to the product, I recommend it 100%:
http://cgi.ebay.com/SHORT-50cm-CAR-AUX- ... 500wt_1156
*I haven't tried any other OFC Aux so can't really recommend another brand. Just a warning that alot of OFC Aux's don't do ANYTHING and are just a gimmick. If u tried it out let me know what u think, thanks.