1) Wasn't this supposed to be a simple bolt on application?
2) Why would you or anyone else want to have to cut up their bumper to make it fit?
3) Wouldnt it be simpler and get a much better acceptence if it fit properly? As in a smoother, less harsh corner like the bumper? To make it even more clear, when making the diffuser, instead of using a 1/2" dowel to bend the corners around, use a 3" dowel to make the corner smoother and MORE ROUNDED.