Are those 4 bolts the only attachment points for the bumper? It would seem to me like there should be more, but I've never seen inside a contique bumper, so I wouldn't know. Also, although I will check those points, that fix seems to make more sense for the bumper sag problem, which is even (more or less) across the entire bumper. My sag+distortion only occurs on the passenger side.
Also, when I get a chance, I will put up links to resized pics. I checked them when I was at school (I can't check the load times from home) and they load unbearably slowly.