Get some long tube headers and a good catback exhaust then your engine will roar.
I think he was more afraid of the fact that you were driving a 426hp Camaro SS and he was most likely driving a previous generation 300 hp Mustang GT.
The Camaro SS is bad axx, but the stock exhaust really isn't all that impressive to say the least. I watched a guy rev his 2010 Camaro SS at a car show and everyone was like
I that it?