EMD Auto Audi A4/A5 Quattro B9 (2017+) Rear Sway Bar UpgradeDescription For those looking for the next step in improved handling, we are pleased to release our rear sway bar upgrade for the Audi A4 A5 Quattro (B9). As the world's first upgraded sway bar for the B9 platform, our sway bar has gone through months of development and testing on our in house A4 Quattro. Intended to be paired with our lowering spring kit, the rear sway bar upgrade will dramatically reduce body roll to create a more neutral steering