The Citrone rides on hydraulic "hand grenades" as they are lovingly referred to. It's a system based on cylinders/pump that actively adjust the ride as long as the engine is running. I used to maintain Francis Coppola's Citrone in Mt. Kisco, NY. It was about the only car that could support his weight.
You may remember the cars squatting down when the engine is cut. His car barely got off the ground.
Another interesting fact... The 2cv was a 400cc engine making less than 10hp. They still did 60 mph., and around 60MPG'
Beside the tower they have there, the Citrone is about the best thing they ever made.
Unfortunately their scooters are no where near the same.