I basically put in four posts about 8'-10' high and attached this cover using ratcheting tie-downs. It works fine. However, when it rains, the cover does sag quite a bit in the middle (when dry, it's about 6.5' high and when wet, about 5' high). It would have been nice to have some reinforcement stitching to prevent too much sagging in the middle.
*** UPDATE 8/23/2011 *** I've had the shade up for about seven months. It's been working great until recently. Unfortunately the stitching holding one of the corner steel D-rings has failed/ripped. I examined the other corners and found the some fraying also, which indicates eventual failure. I guess I'm going to have to repair it, since I don't have any warranty information. But otherwise I've been really happy using it as a carport.