I have a 2010 Focus with the Sync feature and have only been able to find one harness on Crutchfield.com but it has an LCD display that isn't needed for my car and makes the price 200 bucks.
I have found 1 other place with what looks like a compatible harness minus the display for 100 bucks but it's a place I've never heard of and don't want to get ripped off.