[mschuep]

this is the kicker

"An exhaust system shall not be deemed to prevent excessive or unusual noise if it permits the escape of noise in excess of that permitted by the standard factory equipment exhaust system of private passenger motor vehicles or trucks of standard make."

1) Argue you are not louder than stock, 2) Take it in and tell them it is stock, 3) Switch back to stock

1) is a pita, and would most likely involve some sort of court ruling, it could be easy, but could get ugly if you got an a-hole judge. I am an acoustical consultant so I could tell you about the ugly if you want.
2) is a lie, could also work if you got lucky
3) is pretty easy and would most likely work