I have a lot of stuff in my truck now but I've bought several sotrage bags for them. I use a wrench roll and tool roll, these are fabric sheets with small pockets swen that veraious wrenches and tools slide into. You then roll them up and they tie or buckle shut. I use those ties and buckels to attach them to the frames of the seats they are stowed under. Same with the GHB/first aid kit under the drivers seats, it has a carry strap that I unhook and wrap around the seat frame and then hook again so it stays put.