So, after searching and searching, I've found the following 3 items that can connect to the SAT input on my OEM headunit and produce RCA inputs, which I can then run to a headphone jack.

This is so that I can plug in an mp3 player, or use my phone's bluetooth headset to control calls and music.

Now, has anyone used any of these? I've seen prices on them, they seem to go from the PIE, Blitzsafe, then USA-SPEC in price (low to high). That leads me to think they may rank in that order in quality.

Sadly they are all near-ish to $100 which to me, is a hard add-on to swallow when I can just buy some cheapo radio with and AUX input on there already...

 

I have a USA-SPEC and it works great for me! Connects to the CD Changer port so if I wanted SAT I could still keep it. Sometimes it'll suddenly lose the connection so I have to unplug it and plug it back in. It's not really a big deal for me because our cars are so easy to pull apart, but it is a pain, especially when it cuts out while you're driving.

 

This may not be entirely related, but I'll post my 2 cents just in case it helps.

I've got the PIE iPod interface, and it works brilliantly in my '05. The iPod can be controlled via the head unit or the iPod directly (by pressing the number 3 on your saved station buttons). It displays three lines of the .mp3 tag on the head unit, for the name of the song you're currently playing, as well.

Installation was a breeze, as well, since it was all plug-n-play. I did Dremel out a bit of my center console pocket, so the iPod sits in there, hidden from view. But, they give you PLENTY of extra cabling. You could even wire the iPod in to an arm rest, or even the back seats, with all that spare cabling.