That is the SE tail panel piece. I think it was also available with some other trim options as well. As you can see, the rear quarter trim is incorperated into that piece. If you don't plan on using it, you will have to get the separate tail panel trim that the regular cars used. I got mine from Mike at BE&A. They are very nice pieces. You need to keep the holes in back of the quarters for the new mouldings but I don't know how that piece mounts in the center of the car.
