For what its worth just pick up some rubber hoses and insert it to your ACS springs when you get them. This guarantees silent performance so you don't have to worry. Lots of springs actually comes with this. $5 part and takes a few seconds to insert them.
My ACS springs are awesome now. Perfect drop and the handling is just firm enough without sacrificing ride comfort at all. Comfort mode is still comfortable while Sport feels like how a bmw should.
2014 LCI 550i M Sport | 3D Design Front Spoiler | BMW Performance Black Grills | BMW Performance Trunk Lip | BMW Performance Diffuser | Painted Reflectors | Wincos 30% Tint | Supersprint Exhaust | ACSSprings | MORR VS8.2 Rims 20x10R and 20x9F | Michelin PSS Tires |||More Photos of my car here|||