Some details I had not seen before regarding the mechanical operation of the disengaging anti-roll bars that will be available on the upcoming Advanced Off-road Technology pack:

The engagement mechanism consists of front and rear claw couplings positioned at the center of each anti-roll bar.

The hydraulic system for both coupling mechanisms is located in the left hand D-pillar and includes a pressure pump, valves reservoir and tank(Pentosin reservoir). The front and rear couplings are operated using a single control on the center console, which is linked to the hydraulic unit via the CAN (Controller Area Network) bus.

When the driver selects 'disengaged' mode, the hydraulic system increases the pressure at each of the couplings. As the couplings open, the two halves of each anti-roll bar become disengaged from each other, thereby reducing the transfer of force across the axle and increasing the independence of each wheel.

When the driver re-engages the anti-roll bars, the system reduces the hydraulic pressure, allowing the spring-loaded couplings to close and re-establish the link between the two wheels on each axle. The spring loaded couplings also ensure that the anti-roll bars remain engaged if the hydraulic system fails - an occurrence that would otherwise be extremely hazardous when traveling at high speed.

In order to maintain the sports car-like handling and safety of the Cayenne during on-road use, the anti-roll bars can only be disengaged in low-range mode. At speeds in excess of 31 mph the anti-roll bars are automatically engaged.