Hello, i have the Same Problem i have an RNS-E in my Audi S3 8l, i have retrofit it in my car with an Mini ISO Connector to the RNS-E Quadlock Connector. Now i have read here that i must connect the Pin 10 of the 20 Pin Connector to ground.
Because on this Connector the Pin 10 is on the Yellow Connector and this cable are not connected to the cd changer.
Can you say me wich cable on the Quadlock RNS-e Connector i must connect with ground??