The Ami is what, 6500€? Paired down, just the thing for no frills, short distance travel. Both the Zoe and Leaf are in a class above. I'd like to see a similarly low cost 4 seat option.
The Ami is already at the weight limit for quadricycles. If the four seater version weighed any more it would have to be classed as a car with all the extra rules that entails.
Citroen don't make one but ZOE or leaf.