- Forum: iPhone
You have no clue what you are talking about. The CarPlay compatible stereos are nothing but touchscreen display stereos. So when you plug in your iPhone via HDMI and USB, the UI comes from the iPhone via iOS 7. If the iPhone is not plugged in, the touchscreen displays the audio settings and/or Navi from the stereo itself to function as a regular stereo. The concept is ease of use while driving. Simple icons are what is needed in the car.