I got the new cable. The new cable when compared with one installed has just 2 more wires, I copy the info below somewhere, sorry for the author I can't quote him,
If you swap from a mono bluetooth like 9w3 to stereo 9w7, the streaming bluetooth will only come out the right speakers. If you want stereo streaming bluetooth you have to add 2 wires from the bluetooth to the stereo.
If you want to DIY harness, here are all the parts. You need 2 VW repair wires. Cut them in half, solder w/your own extension wire in the middle, and plug them into the existing connector. Connect pin 5 to pin 5 and pin 11 on the radio to pin 4 on the bluetooth.
The new cable has 4 wires - TEL R+ / TEL R- TEL L+ TEL L-
and another 4 wires - CAN BUS L / CAN BUS H / 12 Volts / GND
Finally a cable that goes to the MIC.
On the previous cable I had all the wires with the exception of TEL L+ and TEL L-, so I only added 2 wires from the 54 PIN connector (connects to the Bluetooth unit) to the 12 pin connector (connects to the RNS510)
I took the car to a VW service center and the guy showed me the machine (VAS XXXX) stating everything OK but could not communicate with the control module...