So, I have the USB and 3.5mm AUX input like the rest of us on my 2010. Long story short I started with the Kia cable then moved to a USB dock extender so that I Could put the phone up near the dash for navigation. Fast forward to xmas and I got an iPhone 5.
I purchased the iPhone 5 lightning dock connector and it works fine. I have however, 3 different cables & connections just so I could maintain control from the stock head unit, charge and have quality sound. The solution has been OK, but call quality is less than the optimal I thought it would be, works funny with stand alone apps, and Siri does not work at all.
Ultimately the mess of cords plus the issue of plugging in every time and destroying my battery got me thinking about bluetooth options.
Enter the Amazon.com: Griffin Technology BlueTrip AUX for iPhone and Smartphones: Cell Phones & Accessories and I think I found a winner. I realize I will lose control from the head unit, and also "worse" audio quality, but I will gain bluetooth for calls / nav / music and can use a custom length 3.5mm cord to keep things neat down in the coin tray area.
I think this is a great solution for the Soul particularly because the USB port stays free and battery power issues are not an issue like some stand alone units. I will post pictures when it arrives later this week and also my impressions if anyone is interested.