I graduate in a month from high school...and my dad OK'd it for me to get a couple performance parts for my 335i....dinan software, a BOV, and exhaust....as of right now im certain about the dinan software...and a AA BOV...but im not sure on which exhaust system to get....ive been watching videos on youtube of different sounds but that isnt really any help considering A. a video camera captured the sound...B. not being able to hear in person...so i need some suggestions on different exhaust systems...price budget right around 1500 for exhaust...so far i like the Rennart the best....but i wouldnt know...so i need some advice guys...and also on the AA BOV or another brand...thanks guys