Probably the easiest task of any patch-paneling job is the cutting--but it's also the easiest to get carried away with! Know exactly where you need to make your cuts before you even pull out the Sawzall or cutoff wheel. If your rusted areas penetrate farther than the patches, you'll need to rethink your game plan and come up with filler pieces. In most cases, a brace should be run between the rear quarters to avoid any caving in. (Notice the spare tire well has been cut--a Mustang fuel tank will occupy a majority of the trunk floor space.)