There is a relatively new system in place to restrict polluting cars from French cities. This applies , at the moment, to Paris, Lyon, Grenoble and several other cities. The list of cities is likely to grow 🙂 The cities can “ban” or restrict certain types of vehicle, depending on their level of pollution.
There is a scheme to buy a Vignette for your car which identifies the EURO pollution rating, and this must be displayed on the vehicle if you enter on of these Zones. These vignettes can be purchased on line.
Here is a link to the AA site that details the scheme.
And here is the link to the French Government site (there is a button to change language in the top right)
Hope that you find this useful and as always if we can help then get in contact.