I don't see why unless the 05+ mustangs require a different gapping tool other than the ones that you can find for a dollar or 2.
Have you guys seen our plugs? You DO need the tool, and you DO need to gap them. You can't just use a gapping tool for an L-strap ground plug, like the kind you get out of the bin for $.50 on the counter at pep boys...these are fullstrap plugs.i dont think you need that certian gapping tool any gapping tool will work