Tom, I am in agreement with Marco regarding this floor mat. Any additional rubber matting under the seats would have interfered with the access to the floor mounted tool box that is found under the seats in some models.
BTW, yesterday I acquired the only other roof mounted tail light bracket that I have seen. This unusual bracket is clearly shown in the parts manual along with the mounting hardware. I got deducted for the hardware at both National meets, as apparently the judges were looking for carriage head bolts.