General Motors has been making Active Suspension components for years now but the newest version is called Magnetic Ride Control. This system uses magneto-dampening technology.
The way it works is that a spring-like damper is filled with a polymer liquid containing many small magnetic particles. The dampening characteristics of this fluid can be changed by applying a magnetic field.
A microprocessor continuously reads driving conditions and electrically adjusts the stiffness of the dampers hundreds of times per second. General Motors is actually on its third generation of Magnetic Ride Control. It is installed on cars such as the Corvette Stingray and certain Cadillac models.
GM licenses the system to other automotive manufacturers in addition.