Try a Kenwood KAC-M1824BT The number is important as this model has a remote which is the bluetooth receiver - it also handles a radio input. This is the unit MMC SHOULD have put in the new Plus Four but they went with the cheaper 1814 which a) Hasn't got a remote and B) hasn't got a fader control so you can set the balance between the front and rear speakers!!
Cheers!