Heres another example.
https://www.youtube.com/watch?v=_z6OEohnPKw" onclick="window.open(this.href);return false;
I've not had this happen with stock bushes but they're slightly convex, which is whats needed. In fact, Brickwerks had issues with the early gearbox mounts and had them made with cavities in them to reduce the vibration they were getting in tests.
Despite the hype, powerflex bushes are not always as good as stock ones. I ran all kinds of bushes on track racing bugs in the 80s and they could be a pain in the ass, literally. More recently started making my own so I could get the composite and shape just right (you can buy the raw materials). Currently you don't get any say in the hardness of these off-the-shelf modern bushes, or indeed the shape. Perhaps over time, they will get them right. Until then, reshaping them yourself is about the only route for swinging arms. We just shouldn't have to
