All that work with sound deadening makes me wonder about what I think is the number one cause of such noise: On my Lexus ES350 it seems to be tire noise. When I drive on new asphalt it is so quiet. But on standard pavement there is this pervasive roar. Is it high mileage tires? Why aren't you sound deadening specialists trying to analyze tire noise?? My Lincoln Town Car is so much quieter (Yokohama tires).