I'm surprised these haven't been mentioned here on EvoM (at least after searching a bit) but I think this a pretty interesting product that I wanted to share with the community. Makes sense in theory and there is a nice detailed article of this being installed on a Nissan Skyline R34 GT-R that you can read here at Speed Hunters.

Here's a video explaining the rigid collar and how it works. Luckily, they make these for the front and rear sub frames on the Evo V through X's.

http://www.youtube.com/watch?v=L_h-2...layer_embedded