Thus, although fully active systems remain rare, simpler, less capable but more economical solutions have proliferated. This is the case, for example, of active roll control systems, which have become very popular for Sport Utility Vehicles (SUV). They can make the SUVs feel more “car-like” when on the road [Parsons et al., 2000] and they are not as costly as fully active solutions. Some examples are Land Rover’s Active Cornering Enhancement [Parsons et al., 2000] introduced in 1998, BMW’s Active Stabilizer Bar System presented in 2001, Toyota’s Kinetic suspension (initially developed by Kinetic Pty Ltd and Tenneco Automotive) commercialised in 2003 on Lexus SUVs, Mercedes’ Active Curve System, or ZF’s Active Roll Stabilisation. In general these systems rely on having an anti-roll bar with controllable stiffness. This is achieved, for example, by splitting a conventional anti-roll bar into two and connecting both ends through a hydraulic actuator. The actuator can then be asked to remove all relative motion between both sides, to let them rotate freely, or to do anything in between. Thus, the system can provide tight roll control when driving on road (both axles are rolling in the same direction), and disengage the anti-roll bar in off-road situations when maximum articulation is needed (axles rolling in opposite directions). Moreover, this system can be easily combined with either air springs and/or semi-active dampers, as done in Mercedes’ SUVs.