I have a 1999 323i and i want to make the exhaust car a little louder without having to pay a lot of money. So I saw that a lot of people have taken off the rear muffler. I was wondering if that is safe, because I thought that the muffler usually provides back pressure for the engine. So my questions are, does it affect the car at all if i take it off? Does the resonator at the front provide the back pressure? Is the rear muffler on there ONLY for making it quiet?