roof flashing from lowes, rubber bedmat works awesome, and u can buy it by the foot at lowes, old rubber doormat. sheet metal screws into the inner lip by the frame, few more at the bottom on the frame to hold it down so it dont flap. make sure u make it longer then the wheelwell so it dont look retarded. ive alwats made my own on all my rigs. just google it and check out pics on pickups to get an idea