My guess is that if it were the law, then you could not have purchased it without it. Kind of like California Emission Laws. You cannot buy a vehicle there without the modifications done to it. I would assume the same is true for all states. You cannot buy a vehicle that cannot be inspected in that state. if you have an inspection sticker, you are fine to drive. Now there may be something about hauling rocks, sand, etc inthe bed without a cover.