The all weather cover comes with three white rods. These should be installed into the bottom seams of the plastic so that the cover keeps its shape while riding.
Some trailer seat covers may not have the holes in the fabric. Please add the holes in the seat fabric using a ballpoint pen, gently pushing into the fabric and opening a hole for the bolt to pass through.
Here are additional instructions:
Insert the white stiffeners into the seams on the bottom of the plastic rain shell.