WAHOO some hits! Thought this wasn't even getting use! but i guess no reply are better than a ton saying its not working!

@kowpeki nice job! stoked you could make it work and that my ideas possibly helped yours!

@ Gonzo-2: I think it might just be "au. grd" for audio ground? but that is just a guess. How I have it set up it will just cut out the cd audio and play, not over it as you can't hear the cd audio if you turn it way up (I use any cd(all with music on them also)), I have no clue how it works... but it seems to haha when it does change cds all audio stops, as a cd does have to be spinning for it to work
I guess it isn't a true aux in, but best i have found!

@djsfrigidX: I would say it's a little quieter than cds, but it also really depends on the type of MP3 player you have, I was rocking a sansa clip+, which I found to be a lot louder(at par with cds) than my recent sony E series, Sounds quality is great in my opinion. I haven't noticed any noises or whining with increase of rpm's with my mp3 players, but Ipods are strange, as i think i have experienced the same results as you are describing. So maybe it is just ipods that dont work that well? OR maybe check your solder points, and especially the ground! I didnt have pictures of how i hot glued around the solder points, but this could also be helping in isolating and grounding everything? yes i pop in quite often usually to see no posts!