Aluminum is good for resisting corrosion, but it is usually less rugged than steel. For a truck bed there are really tough plastic liners. Can also get a Lear

Aluminum is good for resisting corrosion, but it is usually less rugged than steel. For a truck bed there are really tough plastic liners. Can also get a Lear or some such cover for the bed. For a steel bed, get something to protect against corrosion, and for an aluminum bed get something to protect the aluminum if it is too soft.