Audrey Tautou is in my opinion the best possible choice for Chanel!
I don't really care if she only did the ads for the money as pretty much all the celebrities who participate in these ads do it for the money. I don't expect any of them to understand fashion.
But i don't really think that's the case here, as due to Audrey's role as Coco Chanel, she had the chance to know more and appreciate Chanel's history more than any of the previous actresses who did Chanel ads.