The filler they used is 3M Automix 5895, a two-part flexible epoxy adhesive designed to repair TPO plastics. TPO stands for Thermo Plastic Olefin and is what many bumpers are made of. Our Crown Vic bumper is actually made of urethane, but this stuff worked just fine. The filler comes in two tubes. Squeeze out an equal amount of gunk from each tube and mix together thoroughly but quickly. It dries to the touch in only five minutes.