Non Mopar question.

I'm "helping" my buddy with his Chevelle today. We can't figure out what this thing behind the back seat is/is for.anyone have any ideas or know exactly?

http://i76.photobucket.com/albums/j12/jcmini30/General automotive/IMG-20120204-00887.jpg

http://i76.photobucket.com/albums/j12/jcmini30/General automotive/IMG-20120204-00888.jpg