I just bought a neat device that adds Bluetooth to an aux input. It works great with no loss in sound quality. I leave mine plugged in all the time and never have to touch it. I bought this because I listen to music through my iphone. The phone has a water proof case and it was a pain to plug into the aux jack.
Seems like you guys adding the plug to the stock radio could add one to the back of the radio somewhere. Then you could hide the Bluetooth adapter and your system would be completely wireless. People would be wondering what AM radio station you are listening to with all the cool music and no commercials.
Here's a link to the one I bought.
Amazon.com: Rockford Fosgate Universal Bluetooth...