Then the couple living down the road from me would have to pay the same for their Tesla as their neighbor would pay for their Ford Mondeo. When they drive past me they are emitting the same amount of nose to the roadside since all I can hear is wind and tire noise. Then you could measure the noise inside the car instead (or it would be a race to the bottom of who will put on the worst tires from the factory) and a huge Mercedes SUV would be dirt cheap compared to an old Nissan Leaf.