Hi guys, I need some ideas.

Both of my bumpers, mainly the rear one, make a real racket when you gently thump them with the palm of your hand. They give out a loud hollow plastic on metal bang like there loose or something, yet they seem bolted in ok, and line up with the body ok too.

I have a funny feeling they are what I'm hearing coming through the car, going over sharp bumps in the road.

Could something be coming loose, or do you think I should undo them and whack in lots of rubber between them and the car?

You could replace the clips, nearest the wheel arches, as a start. If the plastic bumper has loosened its grip on the reinforcement behind it, perhaps try some silastic to stop the vibration. I gather you'd rather not replace the bumpers.

Yeah I'm keeping them. The rear one was resprayed late last year.