In the event anyone cares, I did what I said I wouldn't do... went bluetooth. I am using the Blackberry Music Gateway from http://www.shopandroid.com/blackberr...y/9AA11438.htm
Actually ended up working out way better than I thought it would, my only issue is that the bluetooth volume on the phone isn't as loud as the line-out port. With that said, the difference is negligible and only noticed when you're at the very end of the volume range the stock sound system can handle. IMHO, the sound quality is very good, there is a slight white noise you can hear when the music volume drops really low in a song but the actual quality/bit rate of the sound is on par with the line-out. Although, take this with a grain of salt as 99% of my music is streaming from Pandora/SoundCloud/8tracks/etc... which is probably 128-256kbps at best.
As for the phone, it can maintain two bluetooth connections simultaneously, phone/voice (read: all aspects including Google Now voice recognition/dictation/navigation is all handled through the mic/speakers in the car and only music is routed through the Blackberry device and thus through the Aux port. Works pretty good! I also picked up a cigarette lighter USB adapter which I use to charge the phone when it needs it but have noticed bluetooth audio doesn't drain as much battery as I expected. At the end of the day, I still have the single cord solution that I was looking for, so I'm a happy camper... Now the mission is to see if I can mount an inductive charger under the oddments tray, Shangri-La.