Environment Stickers in Spain

I couldn't find any information as to where (eg which cities) the various levels would apply to.

we have a French level 2 sticker and I see that is fine as these are regarded as similar. Not sure what UK folk will do if they don't have one from another country.

other countries have a list of places where each level will (or will not) allow passage.

perhaps it's way too early for all that...?

Hi, just noticed your posts on this subject. We are going to Spain in mid Feb, our first trip overseas with our campervan and are finding conflicting info on diff websites about whats required for the low emission. Is the french crit air sticker considered ok for spain then ? would rather travel with some form of sticker than none at all as cannot see where on earth you get a spanish one from, they certainly dont make it easy. Any help would be appreciated. 

We applied online for the French Crit'air, as we drive through Rouen. I also got for my Trails bikes, 5 vehicles came to £20. Strangely Euro 6 became class 2, Euro 5 & 3 = class 4. Very simple, I'm sure the French police will look out for vehicles traversing Rouen to and from Dieppe after March. Other Cities will follow, I'm hoping the French sticker will work for our Spring migration to Spain. Who knows?