Sony MiniDisc to radio....How?

I have a Sep 2000 Primera 2.0 SE which I purchased early part of this year. The radio/tape unit has an option for a CD changer in the boot, but guess what.....not fitted. My Nissan dealer wanted £450 to fit one and other local companies wanted £230 ish but seem unsure if the clever cable between the head unit and the changer was available, so I left it.

Recently tried a portable CD player and the cassette on a wire thing to get the music into the head unit but was not happy with the quality. Then tried an FM transmitter so that I could tune the radio in to the specified frequency, but as the UK FM airways are pretty full hard to find a blank area on the dial and also seemed to loose the top end.

Now I have just purchased a Sony MiniDisc (MZ-N710) boy has it blown my socks off. I would recommend it to anyone. I now have the bug to get it working in my Primera.

I want to get the line out of the MD into the back of the radio, easy.....not. When I contacted Blaupunkt they could not help me as it was a factory fitted Nissan badged unit. Nissan say talk to your local car audio store and they say try this type of forum. So here I am.

Nissan/Blaupunkt radio is a model 7 649 347 318. Can anyone help?

Regards
Dave