Im sure this has been discussed, but I haven't been able to find the info Im looking for. Ive just put a offroad bumper with jerry can holders on it, and Im now looking for cans to go in it. My question is steel or plastic, and if steel, do they rattle or is there a procedure to doing this with out rattling cans. Just FYI, I live in Florida where it pretty hot year round, so I would assume that also figures in on what type of can I should use.