Thanks for the info! He has a couple different options i am seriously going to consider. It will be a great way to add the ability to listen to an ipod or iphone to my Astro!
You could always install an inline modulator that plugs directly into the antenna, and either put an AUX wire jack in the dash from it, or a Bluetooth adaptor. I did this on a crown vic I had that had a very basic am/fm radio and it worked awesome. I didn't want to change the head unit out, so this was the best option.