USA-spec iPod adapter works fine with mine. Does show a message on the iPhone that says something like "this adapter isn't designed to work with the iPhone", however it works exactly like my iPod does. At the end of that message it asks if you want to enter Airplane mode to limit radio interference. I always click no and it works just fine. Controllable from the radio and wheel controls, charging, etc. Per manufacturer they need to update the device so that message doesn't appear on some older models of the adapter. No issues other than the slight annoyance factor.
