The SuperPro Motorsport trailing arm bushing kit for 2015 Audi A3 Quattro Premium uses a higher 90A durometer material versus the standard 80A to reduce bushing deflection and improve rear suspension consistency under extreme or motorsport use. That firmer compound can increase road and tire noise in the cabin and add some harshness, but it yields more reliable rear-end geometry and increased grip when pushed hard on track or spirited roads.
SuperPro 2015 Audi A3 Quattro Premium Rear Trailing Arm Forward Bushing Kit - Motorsport