Just wondering if anyone that is running an offroad x pipe with an aftermarket catback,has done anything to improve noise levels inside the car. I've put some sound deadening in my trunk, and it's helped a little, but my car still roars at highway speeds. It sucks when my girl is in the car, but I don't mind it to much when I'm driving alone. I'm thinking of putting some high flow cats to quiet it down. Any advice Guys???