Just some cheap satin black stuff. It really has improved the back end. There's a guy who lives near me who loves his Scoobs. He has a blue blob wagon & when I pass he smiles & gives me a wave. I've now passed him twice & I know by the look on his face he can hear a Scoob. He just doesn't relate he Scoob burble to the hatch. It's so funny looking at him turning his head wondering where the noise is comming from.