the back pipe piece that bends over the axle bangs up against the bed?

I recently installed an after-market cat-back exhaust system for my car. My problem is the back pipe piece that bends over the axle bangs up against the bed of the car when the car idles or drives slowly. It's very loud and annoying. Do they sell anything that would sit between the bed of the car and the pipe to act as a cushion, so they don't touch?