How in the world do you drive around w/open exhaust and not get a ticket?

I had just put the AFX long tube header+glass pack on my car and decided to give a little test drive (never even made it over 45 mph). Well I drove about a half mile down the road and back before I had the cops called on me. Though luckily my Neon looks like a Grand Am other wise I woulda gotten a couple of tickets.