John, At the back - if you look at the back of the unit there are sockets for the remote and the remote microphone -I think the documentation for installation also shows where - I can't lay my hands on my documentation just now!!!
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.
+1, had one for a year very good, fitted old style pod speakers down the footwells as did not want to cut holes to fit speakers. sounds reasonably good, but mainly used when stationary or for listening to Co-Pilot guidance from iPod
Adrian
Buggered Off, to a modern none leaky car, heart's still ticking