A very long time ago (1950-60) I remember seeing a Damper advertised. The dimensions were about 4"x4"x36" with a metal case, and flanges on the ends to bolt it down in your trunk, or, underneath the vehicle, somewhere near as possible to the rear bumper. It had a heavy metal bar inside, which floated from side to side, and was moderately dampened and spring loaded to re-center it after a sharp turn. Operates on the same principal as the large Pendulums for dampening a building during an Earth Quake. The objective was, to dampen the momentum of the rear end of a vehicle preventing/limiting overseer/skid.

Does anyone know the original Manufacturer of this device ?
Are there any made today and by who ?
Have you ever herd of this device ?