Warn (makers of Warn winches) used to sell a three-section folding hard cover for small pickups called the Aerocover. I had one for eleven years on my '89 Toyota and was reasonably pleased with it. Its most notable headache was a big one; the operating handles were in recessed areas on the top, which would fill with water and freeze in the winter.
When I bought my Tundra in 2000, I found that Warn had sold the product line to Rugged Liner. I contacted Rugged Liner to inquire about the Aerocover for my Tundra and learned that they wouldn't be making one. They tooled up (molds cost money, y'know) for the T100, claimed that they got burned when Toyota dropped the model, and refused to risk the investment on the Tundra.
So, I have an
Advance Cover on mine and have been very pleased with it.