It's been my experience that if you're driving a muscle car, cops really don't care how loud your exhaust is. Just recently I got pulled over in my Z28 for some lights not working (crappy old wiring). It has no exhaust, it's just running open headers with 2ft extensions bolted to the collectors. The cop and I talked about cars for a little bit and then he let me go, he didn't even say a thing about the exhaust. Now, I've had friends who drive rice rockets get pulled over and get hammered with tickets for loud exhausts. It's a double standard... but one I can't argue with