Mounting my 12v battery (with top posts - can't use a side post)) between the rear frame rails and next to the fuel tank. Anyone make a cover (lid) that I can place over the top posts? Don't have the room for a marine type box container unit...has to be a lid (approx 11x7). Using a stock GM battery tray on the bottom to lock it in, would like to run a nylon strap around the battery as secondary tie down and to also hold the lid down. thanks