... with wire harness, easy to install, no damage to original car decoration· High-fidelity signal transmit, vibration and interference proof, ... 3GS, 4G>> Installation Steps1. Before installation, switch off the car electric power, take out the head unit, and find CD Changer port ... YATOUR Adapter and iPod/iTouch/iPhone.3. Switch on the car electric power and run the Head Unit, check whether YATOUR adapter ...