I am about to purchase a new Z06 for shipment back to Aus (and pay as much again in taxes and conversion to Right Hand Drive). Does the factory change anything on these cars that I should be concerned about to conform with individual state requirements - eg emissions/noise/lighting/etc. The car I am looking at is in california - should I be looking elsewhere?

Wont matter where you buy your car. There used to be a difference between california emmissions and the other 49 states but I dont think that matters anymore.