All this was a bit new to me and given that we go to France quite a lot I saw it as important. At first I thought it only applied to the centre of Paris and Lyon, a bit like Milan. My impression was also that it was a useless bit of bureaucratic nonsense as in Italy they simply use the Euro category for this purpose. However, after a bit of research, I can see the sense of it. But also I see that the number of zones and cities that require the Crit'air sticker is ever increasing. The main thing that anoys me is that it should apply to the whole of Europe. If every country does its own thing it finishes up a lot of hassle for people who travel a lot.
Having said that I discovered that
Vehicles for which a Crit'Air Vignette will not be available
Vehicles for which a Crit'Air Vignette will not be available
Please observe on indication of your vehicle's approval date and car type that older cars normally cannot obtain a Crit'Air Vignette.
For this reason you cannot order a Crit'Air Vignette for the following car types and approval data:
No order possible for passenger cars having been registered before 1st January 1997.
No order possible for commercial cars < 3.5 tons having been registered before 1st October 1997.
No order possible for motorized two, three, and light four wheelers having been registered before 1st June 2000.
No order possible for trucks and buses having been registered before 1st October 2001.
I also found that there are sites offering the service at vastly inflated prices. To echo John V6 earlier make sure you are on the official site.
I think this is it for the application
https://certificat-air.gouv.fr/en/demande-ext/cguThe home page is
https://certificat-air.gouv.fr/en/