With the way that the quarter panel is buckled by the tire, I would recommend having the frame checked to make sure it hasn't bent... Most likely it bent/buckled the frame on the top of the curve where it goes around the rear axle... If it is bent, a good frame shop can pull it straight...
There is a frame shop around here called Frame Tech that specializes in frame pulling, that's all he does, he doesn't do body work.... He's so good that he usually has a two week back log... If Ernie can't pull it - it can't be fixed.... Many of the body shops around here bring their frame work to him as they don't have frame pulling machines... Then the body shops do the rest of the work after he gets the frame straight again...