Your BMW's trailing arms are a critical component of the rear suspension. They act as a mounting point for other suspension components and it acts as an integral part of the entire rear suspension. The mounting bushings which attach the trailing arm to the chassis are prone to failure over time as they have to constantly battle with excessive deflection.
Future Classic's Teflon-lined spherical RTABs completely eliminate unwanted flex, allowing far more precise suspension tuning and faster lap times without giving up any additional NVH. Rubber dust boots on the outside keep debris out and keep the grease in. This is one of the few serviceable bushings in the rear suspension (the rest require complete replacement of the suspension arm).
Together with FC's popular reinforced trailing arm set, they are an undisputed improvement to your rear suspension stability and, by consequence, driving confidence.