Do i need this for my bumper?

Ok i just removed my fender and bumper to put on the ones i got off a junkyard. Got into a little accident but its all kool now. After installing everything, i see this one foam thats supposed to go betweed the bumper support and bumper cover and I was like . Is it that important or i shouldn't bother with it? i dont want to remove that crap again lol.
http://x12.putfile.com/1/1022330541.jpg (http://www.putfile.com)

no its not important its just there to keep ur bumper hel exactly in place