Hey, guys so I haven't been too active on the forum lately because of school and work but I've been saving up and I just pulled the trigger on a Borla exhaust from a buddy. He had it on his M3 for less than 100 miles and decided it really wasn't for him so I took it off his hands. I called some exhaust guys near me and got an estimate for the custom retrofit so I'm pretty excited and ready to go. My only question is do you guys think I would have to just get a new rear diffuser or would I need a new rear bumper and diffuser. Let me know what you guys think