With the chains off the car, Ferre checked the work so far. He showed the students that the most efficient work isn't necessarily the fastest. Taking time to check progress often helps avoid mistakes. Also, with a panel as badly damaged as ours, you'll need to look for clues to figure out how the it's supposed to look. From the factory, the taillight panel on our Mustang had a strong inverse vertical curve, but it also curves in slightly along the horizontal line above the bumper mounts. This is important to know because the temptation would be to pull until that line is straight. Instead, we needed to square up the gas tank opening in the trunk floor just behind the taillight panel, leaving a slight inward horizontal curve at the bumper mounts.