I have a buddy that has a N55 Valvetronic exhaust (
https://valvetronic.com/products/bmw-f87-m2-n55-exhaust) that was used on his old M2 that he no longer owns. He is willing to trade my detailing services for this which I find very attractive. I was wondering if anyone here has done a retrofit to a N55 135i and if it is worth thes modification cost to take this full catback exhaust. Thanks!