I think the box is ok little vid of it running
https://www.youtube.com/watch?v=cBIe8yulbSk. I bought the tail pipe as a straight peace then welded a bend to the end of it then ground the weld down and polished it up. the rear mount I welded a tab on underneath the exhaust to avoid sharp edges and another coming out from under the car with a rubber mount.
https://www.flickr.com/photos/124541083@N02/