The Msport package includes some non-cosmetic things:
220 Self-leveling suspension
226 Sport suspension
It does not mention anything on exhaust. I drove the 50 Msport & Performance and that sounded loud but in a awesome way. Plus it only kicked in above a certain RPM. I ended up ordering a 50 std which I also test drove but alas it was on busy roads and could not get the vehicle up to speed to compare exhaust sounds. But I have the same question, guess I'll find out soon.