The missing cable on the top image cd player is the illumination wire. The blue/yellow/green connector goes straight into the back of a gamma or beta radio. Yellow is pre-amp output, green is for a telephone kit to connect to, and the blue is the cd player input
The 6 disc changer needs an adaptor cable, something like this
CD Changer Cable - VW / Audi - Mini ISO - Car Gadgets BV