New trailer brake install, trailer plug into the back and not working... :-/
I believe that your 2010 Flying Cloud has LED tail lights and clearance lights. It is my understanding that both Volkswagen and Mercedes Benz require an adapter in the wiring to permit the LEDs to be compatible with the tow vehicle's electronics. The pulsing of the Flying Cloud's electric brakes, however, shouldn't be impacted by the comparability issue so that would concern me in regard to corrosion in one or both connectors (I had this problem on an annual basis with the blade type connectors, but haven't had it since switching to heavy-duty round pin connectors).
I suspect that you will need a control box in your Volkswagen's trailer wiring that will permit it to communicate properly with your Airstream. You may have to try more than one VW dealer to find a parts person who is familiar with the trailer towing accessories and will be able to access the needed part. There is a thread here on the Forums where one VW owner purchased the part that Mercedes utilizes for its vehicles utilized to tow trailers with LED lighting and it worked with their VW . . . I can't remember the thread title or who the VW owner was in that instance.
Good luck with your new tow vehicle!
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)