I don't know if proprietary, if Autozone has it, buy it and give it a whirl .

I was amazed the other day when it was rainy & foggy and as a total lark I turned on the rear defogger on my '84 300TD graymarket, ! it works ! .

Wow .

Let us know how thw kit works out .

Usually the wires get thin from years of cleaning the rear window and go open ~ your having the tab come off/loose is an outlier .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better