Bob,
Did you receive the picture of that guy's trunk? I was going to cut one side of a piece of square tubing but I think it would twist/distort because of the way they make tubing. When you cut it that much, it kinda distorts. I was thinking of just slicing 5-6 inches off of one side at each end and leave the rest as a box. Still looking for a metal fabricator that can just bend up a piece of 12ga but the pricing is ridiculous......but I'm a 50cents for a cup of coffee type of guy (old).