I have just bought a Sony MEX-BT3900U from Halfrauds for less than 100 quid. It has got Bluetooth, IPod, IPhone, USB and auxiliary connections apparently. More importantly it comes with an infra red remote which I keep on the tunnel with one of those sticky silicone pads. I don't really understand all these terms - in fact my son had to point out that the "I" in "IPad" did not stand for incontinence.
One great point in its favour is that it was very easy to fit, even for me.