What source do you mainly listen from? The quality from the radio isn't great and if you're using the aux input, make sure you have it hooked up to the audio out instead of the headphones jack. Also, make sure your mp3s are at least 192kbps and up. 160kbps is ok, but try to stay away from 128kbps. I listen to mp3s via the cd changer and the mids and highs sound pretty good when listening to mp3s at 192kbps. I have a similar setting to the one Acezoned mentioned, except I have the 80hz on the EQ setting up almost all the way and on the tone setting, I have the treble set about +4-5 over flat and the bass at about +1-2 over flat. If you want more bass, best would be to go aftermarket. Just make sure to adjust your EQ and tone settings accordingly; with the subwoofer in, I have both the frequency at 80hz and the bass control flat because I can control the bass using a bass knob. As far as mids and highs, seems like a lot of people here have gone with the BSW upgrade and are happy with it. Good luck!

__________________
If you feel the need to bash/rag/insult/demean someone, please read this before you do. Thanks and have a great day!