Even in the 1990s, a Xantia would be a cheap way to buy a luxury suspension. Still amazes me that my '74 DS and my '98 Xantia can use the same hydraulic fluid. Even the pressure spheres are interchangeable, although not advisable.
The very worst was the SM, which overcomplicated just about everything. If you open the hood on one you'll have at least six "WHY?"'s going through your head at once, the kicker being the rotating shaft over the top of the engine to drive a pump on the other side of the block.