None of those items are REQUIRED! Exhaust, depending on the kit could be required....most certainly recommended to get the full potential of the kit.
Brakes, suspension, clutch.....No.
2016 Individual f80 M3 - San Marino Blue/Full Amaro
2012 MR e92 M3 DCT, fully loaded... GONE but not forgotten!
2008 e92 M3 Coupe 6MT | AW/BLK Extended...SOLD!