I made a gutter based on some photos I saw here and on other sites. I went to the plumbing section of a hardware store, got a piece of pipe, cut it with my Dremel and it works great! It snaps on so securely I probably could (but I won't) drive with it on. I made my side cuts smaller so mine doesn't so much lay on the tent as it clamps on the roof edge so it's pretty solid. Great mod especially here in swampy Florida where the A/C is running all the time.