Use SE V600i and Nokia 3230 and had no problems pairing them up and they both work fine in my X5 but obviously no Sms and no contacts exchange!My wife has the SE K750i which I have also paired with th BT in my car.Comments on the 750i are that the loudspeaker is not loud enough and poor video quality compared to Nokia but probably has the best camera quality at the moment and like mine V600i it has a amazing screen resolution.