Ive not been a big fan of the Fiesta adverts, they all seem to be a little too overdone, and following the lines of VW's Polo adverts (i.e.: a tough little car in dangerous situations).
I do however love the new poster ad. Which features the sport edition of the car in the top left of the picture, with the tagline "Loves corners". Its got the subtlety the other ads lack, and I think it works really well.