Turner Motorsport has been in the motorsport industry since 1993, and is in a continuous pursuit to find products to improve your car's performance. That's exactly what they've done with these performance rear differential mounts. Originally developed by Turner Motorsport for their Grand-Am Cup E46 M3 race cars, the advantages of solid aluminum mounts is increased suspension & drivetrain response, less drivetrain loss resulting in more wheel horsepower, and longevity - they effectively last forever. These CNC-machined mounts are a direct replacement for the stock rubber pieces, and have been lightened to remove excess weight. Using aluminum instead of rubber eliminates the "wind up" inherent in rubber mounts, and this deflection slows suspension & drivetrain response.The tradeoff is an increase in NVH.