"...Even after the X-pipe install, the exhaust still isn't that loud," Jared said. "Magnaflow had the answer to that with its 3-inch competition after-cat. Now the car sounds just like a Mustang should." The answer from Magnaflow was the company's Competition Series after-cat system (PN 15590; $809.97) for the '11 GT. This stainless-steel system features 3-inch tubing and 5-inch mufflers with 4-inch tips. Combined with the Lethal crossover pipe, this system provides a throaty growl during acceleration and a mellow rumble when cruising. Nice.