I use magnets as well. I recessed them into the body of the accessory, all 3d printed items, and now they hold on very well to the bed of my truck. I made a frame "crossmember" our of thin gauge metal for this purpose. It also adds support to that area of the frame since I modified the shock towers and changed some other stuff. E6000 felt too permanent for my needs, so I cooked up this idea. Hope this helps.