I have an Android phone that I currently run all my music through. I use one of these to mount it, and then just use an FM adapter. The FM adapter doesn't work great, though, and I've never had one that had great quality or consistency.
This is a stock NON Bose system, and I simply want the audio from my phone (mp3 and video) to go out through my speakers. I looked at the audio interface thing, but for close to 100 dollars, I'd rather save my money and put it towards a real in dash unit. If this is really the only/cheapest way, though, I might consider it.

I'm not afraid of soldering/hacking something up for this.

 

If you have the satellite adapter already installed, you can splice the audio signal line and use that for pretty much $0, otherwise you're going with the $40+ antenna bypass/wired FM modulators or the $100+ line input adapters.

See this thread for more info:
https://g35driver.com/forums/audio-video-electronics/422464-how-add-auxiliary-ipod-input-factory-radio.html

 

u could be old skoo and try one of these lol