I posted this in FAQ but noone replied. I want to do a custom exhaust. I am new to the car mod scene and would like if someone could point me in the right direction via a faq or other methods. I am intresed in doing it my self. Also would like to know the best exhaust mods to use IE muffler, downpipes, anyother things (legal) would like to keep sound reasonable, main conern is HP. Thanks for any help.