Citroën 'Dromos', by Bouvier, from the Centre de Style of Velizy.
This sketch was made in 1983, but as far as I know, it wasn't a real 'project' as such. Just a creation from the designer's fantasy.
The idea was to have a shortened wheelbase and a much higher driving position, for city driving, creating a small citycar, with that articulated rear axle. And then it could be quite longer for higher speed on highway, and much lower as well.
Funnily, it was quite the same concept on the Renault-Matra Zoom, shown at the 1992 Paris Motorshow.