RE: MSD and Exhaust
Are you talking about the Multi-displacement System (MDS)? If so, I have the MDS on my Ram and you can put on whatever exhaust you want. To my knowledge there is no special exhaust system for vehicles equipped with MDS. Your car will be quieter when the MDS engages, but you don't want your car to be loud when you are at cruising speed. If you are cruising and you punch it you will hear a louder exhaust note while you are accelerating. Get whatever exhaust you like.