After having a new b pipe installed, the back box is slightly further back by about an inch. One of the rubber exhaust hangers behind the bumper occasionally rubs against the underside of the boot. This makes an awful noise inside the car. I've tried gluing some rubber pipe in between the hanger and boot floor, it worked for a while but has fallen out. Would putting a big dollop of grease in between cure the problem or is there a better solution?