Ive been looking around the internet at Borla catback systems for my car and on the exhaust section for Mach1s at the RPM outlet they have a page with two different kinds of Borla exhaust. The Borla Stingers and just Borla. The thing is that the Stingers are $100 cheaper than the Borla. What is the difference here that makes one $100 more than the other? I've heard Borla Stingers on a 4V 4.6L and it sounds DAMN good and it's the CHEAPER of the two....... So what does the other sound like? Anyone have any insight on this? Is one more aggressive while the other is a more quiet and conservative or what?