Back in 1975 I put my 68 FJ40 on it's side on an icy road in South Lake Tahoe. The loose Highlift Jack laying behind the front seats flipped up and almost hit my now ex in the head. After that I used a length of chain wrapped around it to keep it place. Used many different containers to carry things. But also figure a way to secure them. The soft tools bags are one of favorites. Few rattles and so not slide like hard container.