I drive a CS and there is quite some "roll noise" from the back wheels, especially when I drive on roads with a bad/concrete surface. I have the Bridgestones replaced by PS4 but for the noise from the back there is no real improvement. I think it's just some lack of noise insulation and the fact that it has 225 tyres? It's the first time I drive a car with such wide wheels, so probably it's a normal thing...
would be happy with your confirmations