My 01 convertible's rear bumper cover isn't quite right on the drivers side. I took off the 3 nuts (1 in the wheel well, 2 in the trunk) holding the side of the bumper on. I was able to see that the piece with the three bolts attached was pulling away from the bumper cover. That piece is sold separate from the bumper cover. So, how does that piece attach to the bumper cover? Thanks.