I put dynamat in my car along with some of that rubber wet suit type insulation but Richards car beats mine hands down. I think his idea of using a duel window is the factor, he has a thick acrylic window and a laminated glass window on the engine side, plus he used some super duper kind of rubber insulation. We could carry on a conversation at 65 mph and not have to read lips or use hand signals, it was a very enjoyable car to ride in.