I've been reading this thread with interest as we just picked up our 2010 Edge last week. I have been trying to get my iPhone 3Gs to work properly with Sync. For those who aren't familiar with the iPhone and its Sync issues, it will frequently not play audio via USB if you turned the car off while in Bluetooth Audio mode or just about any other input except for line in, andd then got back into your car and attempted to play via USB. A huge pain.
After reading this thread, I had a great idea...
I found the USB2 port on the suncc module as mentioned. I then bought a short (8") miniUSB to USB cable plus a female to female USB adapter as well as an 8GB USB flash drive (on sale at Staples here in Canada for $20 this week). I then found a simple software program that scans your iTunes Library and allows you to choose playlists to save to the USB drive. Basically, I had a copy of my iPod on a USB flash drive. Plug that into the USB2 setup and store the whole thing behind that panel in the center console.
Works like a charm and no more issues as above. I will only use the main USB for charging or for other USB sticks if needed. Kinda turns a USB stick into a built in hard drive media player...all for around $30!!