While I was at Zcon in Atlanta I got to spend some time with Gnosez at the car show. It was a lot of fun and very informative. While we were talking, we ended up on the topic of the Bad Dog frame rails that Gnosez makes and markets. John was telling me that when the frame rails get added to the floor boards they should not be fully seam welded. They need to be spotted in with gaps between weld sections. John was telling me when people have disregarded his advise and fully welded the floor seam, cracks have appeared at the roof joint at the top of the hatch. We were wondering about that joint and since Matsuo San was just a few feet away, we went to ask him about it. When we asked him about that joint, Matsuo San said the car needed to "breathe" and they put that joint there at the hatch. The idea was that the movement, from the car flexing, there at the hatch was better than stressing the A pillar and cracking it instead. He also said that since the chrome window frame is not structurally supportive, it needed to be like that. If the door had a real frame around the glass it might have been different. So for those of us, me included, who have considered making that joint more substantial to prevent cracking, that is not such a good idea if you like your windshield to stay in the car.
John may have more to add as he was interpreting for me...