Volkswagen Beetle 2.0L 2012, Stainless Steel Cat-Back Exhaust System by Borla®. AGGRESSIVE SOUND, 2.5" Tubing. When you want the best performing, best sounding, and highest quality exhaust system, you want Borla. Borla straight-through mufflers and mandrel-bent exhaust tubes are custom tuned to deliver the most horsepower possible, with that famous Borla "growl" of power. And the quality, aircraft-grade, austenitic stainless steel construction allows Borla to back every Cat-Back system with an unequaled million-mile warranty.