OK. After exhaustive searches (and a lot of badly translated (bablefish) french renault forums, it seems the 2005 > Renault radios are now made by alpine rather than VDO, which means the VDO CHM 604 MP3 changer won't work.
However, I'm not one to give up easily. I'm sure it's just a din / iso pin config. problem.
So, can anyone point me to a diagram / layout of what each of the blue ISO connector pins does on the Renault radio. It's a REN RDW270 - 10
Also, does anyone know if the radio I/O is Analogue or digital?
Or can anyone give me a really good reason why I shoudn't start messing around.