From what I've heard Vorshlag make the quietest most reliable plate, but it's still metal on metal attachment to the car. You could consider making an isolator pad between the plate and the body out of a high durometer rubber or poly which could help dampen out some of the vibrations and harshness. On the highway my plates act fine, but you definitely get more tire noise through the cabin as a result of the direct metal contact.That ship sailed, I've already slotted about 1/8 inch. I'll have to dig around and see how much more room I have, but I don't think it's enough room. I'm wondering if there's another camber plate that isn't too bad NVH wise that would get me to -3 with a little slotting.