It’s the 034 Motorsport Dogbone Mount Insert. The Dogbone, or Pendulum Mount, limits the rocking of the engine during acceleration.
There are a lot of companies that make the actual Dogbone Mounts, of varying densities to hold everything in place differently, but there an issue with those. They often translate heavy NVH into the cabin as enhancing the whole mount’s stiffness means there’s nothing to take the vibration. The genius of the insert is that it’s cut to fit into the stock mount with its less stiff material. Long story short, it minimizes additional NVH because it’s not a harder material the whole way through. You’ve essentially added a skeleton to the system.
So Long story short is that the engine and transmission finally feel in sync as they should be. And the best part is that the intrusion into cabin is not bad at all. Imperceptable at idle even. I would say I’ve traded an extra 5-10% of NVH under heavy acceleration for an extra 35% drivetrain cohesion all of the time.