So my original solution (I started this thread) worked great, other than a lot of cables in my center console, which is a bit inelegant and bothersome, so I kept looking.
Here is my new solution that eliminates most cabling, and seems to work just as well.
USB Bluetooth 3 5mm Stereo Audio Music Receiver Adapter Fr Speaker iPhone 4 4S 5 | eBay
Also has the added benefit of costing less than $10.
Not certain I can improve on this...
