I did a little looking around but didn't find anything on this. Since the rear seat in my Outback has the two hollow plastic shells on the bottom for it's support I was wondering if anyone has made a permanent ballast in the seat? Could you take those off and fill them with something like sand or concrete to make them a permanent ballast? I'm new to this game so let me know if this idea is just retarded or if there is some validity to it. Thanks