I have looked through some builds and haven't seen this so I assume there is a reason to not. I was thinking that maybe welding a firewall behind the seats, maybe just forward of the toolboxes would block off some noise and maybe add some stiffness. I don't know that I will ever have a full rollbar or anything like that. If it was cut to fit the car, and stitch welded around the edges to the body, would this be of any benefit, or have I been eating to late again and having weird Z dreams?