Also remember that the 370Z is in its "first year" of production. To the insurance underwriters that means the 370Z is not the same car as a 350Z no matter the number of years the 350Z has been around.
That means the insurance companies can make the
claim they have no statistics accumulated yet of the car's overall performance and safety. So they get to set an inflated insurance rate at least for the first production year of the car.
That can jack up the premiums and everyone must suffer through the first year...