Are you sure the water infiltration is not from in the wheelwell and wicking up through the lamination, or possibly a combination of that and from the fridge vent area? One thing is consistent on these things and that is the shitty construction. I have not seen any that did not have some type of unsealed gap in the wheelwell somewhere. Usually you'll even find exposed plywood edges in the wheelwell which is the substrate layers of the wall panel lamination. Spray on undercoating is a good idea in the wheelwells.
