Save your $$.. 10 or 20 mm might look a bit better but to the untrained eye no one will know the difference.
As for the sound.. it's the car not the tires. I had these same tires on a different car and they were not loud at all. I put some Michelin Pilot Primacy tires on my stock sport wheels (found a dirt cheap used set on ebay). They are horribly loud. I don't think this car has any sound-deadening material. Must be a weight saving thing. I drive a sports car so I don't really give a **** but I did notice it. Not trading for a Lexus any time soon
