yeah, car-free cities dont exist. what does exist is cities where you can live a normal life without a driving license. though even there this is restricted to parts of the city i think, where the public transport network is dense enough.
There are major cities that have "less car" zones in their center. Basically they just charge huge fees to bring a car into the area. It is definitely a step forward, but it would be nice if it wasn't "no cars for thee but, yes, cars for me" from the rich.
There are, in fact, some car-free places. But it's largely due to logistic issues (middle of a rain forest or on an island without a bridge. or stupid narrow streets)