aFe Control 15-21 BMW M2 Adjustable Front End LinksImprove handling and eliminate sway bar preload with aFe CONTROL adjustable end links. Sway bar preload is a scenario where your sway bar is in tension when your car is at rest. Sway bar preload affects how the vehicle handles making it stiffer when turning one direction versus the other. Factors like lowering springs can end up with uneven suspension heights which can lead to sway bar preload. If you have adjustable coilovers and are corner balancing