I am in the same problem, with a Mazda 6 though.
I been researching and found this to be the most interesting.
If you have not seen this yet, taka a look at this site:
http://www.sylfex.com/products/AuxMod/
But, how did you connet the iPod to the stereo?
I read all your installation. Looks great.
But my problem is not the battery or how to hold the iPod in a secure place.
My problem is how to connect the iPod signal to the stereo.
I have been hunting for the most direct way (no FM Modulators or...