Well I dont have the iphone 4. But i do have a Verizon phone. I will tell you exactly what i did. I have the 2007 SC 430, but im sure its the same. On the back of the steering wheel (right side) there is a voice activation button, right under it is a telephone symbol (for bluetooth) I pressed it and it brung me to numbers and such, then i pushed settings from there,then on the right side, i pressed the down arrow and saw bluetooth, right next to that was a "Add Phone" Then search on your iPhone. A name should come up. It will say simething like "HANDS FREE" or something along those lines. Then click it and it should connect. If that doesn't work, it could be your iPhone, or the car. You might also wanna call lexus and ask. But that worked for me.