I have purchased several of these Shade Sails. My reason for using this product, is that I usually cover my project cars with a car cover and then a Tarp. However, the Tarps don't last long (maybe 3 months) in the sun and tropical climate where I reside. The Last one of these I purchased has been up for going three years. Experience moderate winds, and only developed a tear due to being too close to the car (car's radio antenna digging into it from time to time). Once installed correctly (with room for sagging/stretching due to water) it will last a good time (maybe 3 - 5 years). You have to pitch (angle) two sides to allow proper drainage. Even though it is water permeable, rain water will collect in very heavy down pours.Family and Friends have been so impressed, that I have begun to purchase more and install at there homes to cover the cars in the drive way. I suggest not having more than 12 -24 of line from each install point. If you can directly connect at least two sides to the post/wall (install point), it will be best. Long lines will cause it to flap in the wind, and reduce the life of the unit. There are more heavy duty versions (260g, with stainless steel wire in the hemmed edges), but I don't think those are necessary unless in high wind exposed areas.