This article is so full of bullshit!
Car are still a lot in Paris and there are conflicting studies about the air quality evolution in Paris, some days it is better, some days not. But the Parisian regulation on car as no real effect so far.
Paris is like at a bottom of a curve and it is said that the car might account only for less than 20% of it, the biggest contributor being industry in the region.
What had a big impact on thin particules are the evolution of car technologies. Now every engine in France has to be equiped with efficient catalytic exhaust pipes and efficient engine to reduce this kind of bad particules.
In this article, you can see a very deceptive image comparison. There is a picture of the Eiffel tower long time ago and now.
The picture of before has a strong fog, but it is just because being taken on a foggy day but the article would like you to think that it is how a picture would have been everyday due to the popultof the air...