rear defroster

Anybody here ever try soldering the connector onto the rear window?It was soldered from factory but I'm affraid the window will break with the heat,as it is cold outside.I bought some glue from a local store here that was made for this purpose and was supposedly highly conductive it stuck ok but no current passed through it.Now I'm thinking of soldering it.

I have never seen this work, sometimes the conductive paste yes.