Interesting gimmick Citroen have come up with on the C5 Wagon - the suspension has an electic pump that works the suspension even when the engine's not running. A level switch at the back near the tailgate makes it so you can change the level from the back - handy to lower for loading, or raising to connect that trailer towball after you've lowered the car first. It automatically raises on rough ground and lowers at speed, too. And of course, it stiffens in corners - I think this is a different system to the semi-active anti roll like the Activa, which I seem to remember lifted the outer side suspension as well, not just stiffened.