first of all, buy a new bumper. Your not fixing that and if you do it will recrack and spread within a few hours of drive time. Second there is no way to properly mold ANYTHING to a bumper like that. Your only option would be to plastic weld some sort of seam the entire way around, then sand it smooth, fill that with a very light poly fill, sand that, spray with 2k urethane primer and paint with a TON of flex agent and it still WILL not hold up. And on top of that if you screw up half way through your out a new bumper and air dam. I'm not talkin out my as$, i am a body man and this is what i do everyday. I'm just trying to inform you of what you can and can't do, and you can do this, but it will not be worth your time or money or will last at all.
