What exactly was wrong with the bumper and how did you straighten it?
The AMD bumper has a crown at the center, so when its bolted to the car, each end looks correct, but the center at the trunk lock is very high, almost hitting the tail light assy.
I clamped the bumper at each end to a straight 4x4 using C clamps and wood shims to protect the metal. The "top" of the bumper (with the crown) was against the 4x4. Had the 4x4 clamped to the workbench. Then every 6 inches I drove tapered wood shims under the bumper, at mid point I had several shims stacked together to force the center higher. I would drive the shims in, then take the bumper off and check with straight edge, then repeat. The shims were from lumber store, used for shimming doors or windows, etc.
