Aha! Further proof that great minds think alike! In my coupe and in my son's sedan, I put a tube across from side to side and mounted everything to it. The main difference is, ours are welded in and the column supports/mounts are different because we are both using GM columns. Yes, it does stiffen things up a lot...

As usual, beautiful work, Don. Maybe Dan should put a lexan cowl on this thing so the underdash detail will show. It's almost a shame to hide all the fine work you guys are doing.