I have a Mazda 3s 2013 skyactiv sedan. I have been wanting to upgrade my exhaust system to sound really good and stand out alittle bit. I was thinking about changing the muffler rather than the whole exhaust system. Oppinions on that? Or should I change the whole system. What would be a way for me to achieve this without spending a lot of money and simple to do. Last thing ,would getting a ram intake or cold air intake change the sound of the car with the stock of the car , would it be worth changing and the money. If so which would be better to do.