After we installed 034Motorsport Billet Aluminum Transmission Mount Insert during the last vist, this 2013 Audi B8 S4 returned a complete front and rear StopTech Axle Packs brake upgrade kits for improved stopping performance. StopTech Axle Packs are pre-matched, direct-fit brake pad and rotor pairings designed to simplify brake service and brake system upgrades and is the easiest way for drivers to replace their existing rotors and pads with high quality, & premium features from the championship-winning team at StopTech. The Sport Rotors that are included in this kit are drilled and slotted to prevent glazing of the pads, add bite and improve wet and dry braking performance. To improve feel and responsiveness, we also installed the StopTech High Performance Stainless Steel Brake Lines that are constructed with a Teflon inner line that resists expansion under pressure. In comparison, the old rubber lines deteriorate over time and can expand, which leads to decreased response time and a softer pedal feel.