Watch this video starting from 5:10:
https://www.youtube.com/watch?v=xJud8MEhntw
Holy Faq! That's crazy aggressive for a 4 door sedan. I was dead set on replacing my M3 with an M4 next, but now I'm thinking get the M3 again. I don't care what the haters say. That quad-center exhaust is just badass.