Blackhorse03

I got my car used about a year ago and I've taken it upon myself to replace the carpeting after my girlfriend left the passenger window open for a good thunderstorm. I've also decided to get the rear defroster working however the car came to me with no grounding cable attached to the passenger side tab of the window element. I ordered the cable that attaches to the tab but have no idea where to put the other end. As far as I can tell theres nothing to attach the grounding cable to.. If anyone has a clue about what I'm talking about any help would be most appreciated.