Brown line in rear quarter window

[Drew Adamson]

Hi All. I just switched to a 2019 A6 Avant and I’ve noticed a thin brown line running at a 45 degree angle from front to back on the offside rear quarter window. It looks like it could be an electrical connection. Can anybody help on what this is?  

[SwiftOtron]

On 4/19/2021 at 5:58 PM, Drew Adamson said:

Hi All. I just switched to a 2019 A6 Avant and I’ve noticed a thin brown line running at a 45 degree angle from front to back on the offside rear quarter window. It looks like it could be an electrical connection. Can anybody help on what this is?  

I’m picking my car up tomorrow, but I wonder if that’s part of a heating system to defrost that window? I had something similar on previous VAG cars, so will check.