Hands free option? 2002 E Class

[Soarsing]

Hi folks, may I ask if any members know of a hands free option that would be compatible with a 2002 E Class? The Mercedes dealer in Belfast sent my wife round to Halfords to get it sorted but Halfords advised that it wasn't possible due to the way the car had been wired at the factory. There is a big old brick type Nokia supplied with the car in the centre arm rest console and there is a six cd changer embedded in the dash console. Any help at all will be gratefully received, many thanks, Arthur