I used to use one of those bungee type truck bed nets. The ones that kind of look like a spider web that stretch across a truck bed. They have hooks all along the sides, so i would just wrap it around the roll bar and hook it. Done. The one I had even came wth a storage bag so I could just throw it in the back of the Jeep until I needed it. WAY WAY cheaper alternative to those custom made cargo nets and did the charm just fine. Of course, my lab is not the most active either.