I just read the details on that link. It says that one is chip board. and ships flat. I must have got mine from someone else. It is heavy cardboard like the one that was originally in it. Was rolled up when I got it. I think I picked it up at Carlisle, so didn't have to pay shipping.
yeah, I think I will just get the hardboard and just make my own panels. I need to go to home depot anyway to buy sheetmetal and square tube to make my new trunk flood