I came across this RAC page today, and have just applied for a sticker for my daily driver. Cost €4.21 inclusive of postage to the UK.
https://www.rac.co.uk/drive/news/motoring-news/law-change-for-uk-drivers-in-french-cities/
Unfortunately it looks like bad news for Traction Avant owners though; I was unable to complete all of the boxes in the form, so from this link anyway it doesn’t look like a TA can obtain a sticker.
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