Concretejim:
You only have to have one displayed where there is some kind of ban based on Euro class.Salzburg/Karnten/Voralberg are the only states of Austria where you do not currently need a sticker. If you are travelling through any other states of Austria you will need one. (Mainly total bans on euro 1/2 class)
Muckles you dont need one on the A10 currently.
The website i linked is quite useful aslong as you understand german. Im not sure if its available in english.
Cheers I’d seen some maps and they didn’t include the A10, but will keep an eye on it and might just get one if I have time as I’ll be going to Budapest later in year.
I have noticed that a lot of Austrian stuff, doesn’t have an English translation, was trying to get a permit to run on a Sunday last year, but it’s their country so I suppose their quite within their rights not to have translations.