Dunno I havn't really payed that much attention to it. What are the mistakes you have spotted?
Firstly Citroen is a French car and secondly they spell unmistakably wrong. Think they are trying to be ironic. Check it out next time the ad is on TV.
The whole point of the advert is too show that they have made a car with all the reliability of a German manufactured car while keeping the French style.
Oh and Unmistakably is spelled correctly.