I wonder how much the width of the current car is to limit roll in corners and help keep the relatively wide rear tyre in half-decent contact with the road given it is held rigidly in a vertical plane by the back suspension design.
Modern cars with massively (mostly un-necessarily) wide tyres now have to have all sorts of tweaks to the suspension to maintain grip/traction
Drove 2CVs for years and they had v simple suspension, plenty of grip and sensible narrow tyres...
