My 2002 S3 shipped new without heated mirrors (yeah I know...). The cables are there for heated mirrors, new glass has been installed with heated elements, and they are connected. But they do not work having tried front demister, rear demister, centre position of mirror adjuster etc. there is power to the fuse but not to the wires. All tests done at near zero degrees C. Someone mentioned that it may need to be coded to enable them. Can VAG COM enable the mirrors? If so how? Any help appreciated.