I do exactly what your trying to do. I went out to Wali World and got a thick tarp that is brown on one side and a light grey on the other. I used a hot glue gun to seal the parts that I didn't want to really ever move and Velcroed the rest, except to make it a little easier I put a pill and stick zipper up the middle and Velcroed the bottom, this way I unzip the middle and then undo the Velcro strips on the bottom and it works for me, saved a lot of hasel with replacing weather stripping all the time.
Adieu