I have the soft TonnaPro style cover that stays down with Velcro. I usually put wood up against the can and leave the cover over it. I use bungie cords that go from the loops at the cab side down to hooks in the bed side. It keeps the cover in place without flapping. I may have to occasionally pull things tight but if the bungie are close to where the Velcro is it holds well and does not interfere. I put my gen and cooler between the hitch and tailgate if needed. I have the Anderson hitch so there is plenty of room.