It was one of my speaker boxes in the trunk.:D
They are up on the tray section right behind the back seat and are actually cut down house speaker boxes with a 10, a 6 and a tweeter in each box.
One was up against the inner wheel well.
That scratch looks like surface stuff and should polish out if it is.
I had just gotten back from the grocery store one day and our Daughter came out to help me carry the stuff in.
She was taking a plastic bag of canned goods out of the trunk and knocked a chip out of the paint on my fender extension with it.
This is just one of the reasons I wouldn't pay for a paint job.:D