6.3 air intake air box




I thought so also on my 09 C63. They're more beneficial when you have other mods to compliment gains. On a stock M156, I don't see them worth the price. The only reason I have them on my stock BS is because I took them off my 09 before selling. If you plan on getting or already have headers and an exhaust with an ECU tune, then go for it.



