I bought an HHR 5 months ago and the panel behind the rear doors is made of plastic and looks like someone took a sandblaster to it. I contacted my local dealership and was told the only way to fix it would be to replace the pieces and put in sideboards. They said I would need to contact GMC through the 800 number to see if they would pay for it. Of course they said no "Its not our problem, its due to environmental issues" Thats baloney. The car is five months old we had a mild winter and it wasnt driven much in the snow. This should have been made better. This is the midgrade model. The dealership said they would replace the plactic, but without the sideboards or the piece being made of a different material, it will look the same in 5 months. Looking at the next grade model that comes with sideboards, it doesnt even have this piece. It appears that they new because it sits low to the ground that this would happen so they just slapped a piece of plastic on to protect the metal, but the plastic is all chewed up.
Solution of your complaint
The piece needs to be replaced with a more durable material (ie. metal or fiberglass) and sideboards.
I will file a complaint with the BBB and since this vehicle is so unique, and Im am asked daily what my thoughts are about it, I will be sure to let people know not to buy a Chevy, because they dont take care of their customers. They wonder why people are buying foreign vehicles.