I had one of the plastic drop in liners in my '05 and used it for carrying T posts, minerals etc. I had it in from Feb '05 till I sold the machine in August of this year. I took it out so the lookers could see the condition of the bed. I also had a heavy steel tool box bolted through the liner and bed down the drivers side. The T posts gradually knocked a hole in the front corner so water and debris could get under the liner. So I removed it and there was a rusty place there in the center and around the bolt holes under the tool box. Nothing terrible because when I cleaned it up, most of the diamond tread pattern was still there. On my new machine, I got a piece of exterior grade plywood ,cut it to fit the bed and bolted my tool box to it with recessed carriage head bolts . It wont slide out easily if you raise the bed as long as you have a thin metal strip at the edge behind the stake holders. My 2011 machine came with a spray on bed liner. so that is why I went with the heavy plywood. Now when I carry minerals, I put then on a tarp. I also sprayed fluid film all under the machine where manure and minerals might get. The drop in liners are great if you check under them from time to time. bordercollie