Well in CA, the police will take the car and we have the "green police" running around also. With my car, it's REALLY obvious I have no cat, if the smell doesn't set the cop off, seeing the header and muffler and nothing else will (not exactly hiding anything without a rear bumper)
My neighbor is a cop -- he's the one that told me what they'll do if I'm stopped. It ain't pretty -- don't have many "rights" when it comes to driving in CA.
My original plan was no cat for track, I'd prefer a cat for street.