According to my car's manual, the iPhone 5 works in USB mode in Accord models without second (touchscreen) display only. Apparently it is not true as I connected it and the music played very well.
This is in the "iPod" mode of the car's audio system. So there you have it, iPod integration works in the 9th generation Accord with iPhone 5. In models with (and presumably without) the second screen (touchscreen).