I wouldnt quite say perfect. If you have bluetooth enabled, and plug the phone in via the Aux as well the music will cut out if you use aux, as bluetooth on the Iphone 4 automatically starts streaming music via bluetooth whether you like it or not. Ive explained how to get round in in the sticky at the top of the forum. Its not too bad though, and the bluetooth phone and music works brilliantly, as does bluetooth streaming (you can skip tracks backwards and forwards with the latest firmware). Its just when you combine bluetooth and the aux cable that things get a little disappointing.