CAN Gateway / Interface 2.0 > 1.6 Radio Adapter

Hello,

I am looking for a CAN gateway/interface.
The following problem:
Car: Volkswagen Golf 5, Variant (estate), 2.0L engine.
Radio: VW RNS MCD, CAN version 1.6 (Navigation system from Golf 4). C)

I installed the navigation system, and it's working great.
I am now looking for an adapter to control the MFA and FIS. Who can help me?
The interface is implemented in the opposite way in this function (Radio version 2.0; Car version 1.6).
Can the adapters work in both directions?

Who can help me?
I am grateful for any help!

It only concerns the arrow representation and the RDS representation within the FIS!
All other functions are available!
Thank you!!!!