I would not recomend this product to a Fiesta ST. It takes a long time to set the car up First when i did it it did not fit propely which i had to buy and extra part wich ws a Focus Spring seat, cost me £30 extra. Then after getting the spring seat when i tride to fit the strut on the driver side it did not fit and i had to grined the hole on the top were the strut therad goes throu to make it fit, because the off set that the caster gave to the strut thread.
Dont let this put you off buying parts from puma speed I have bought alot and this is the first one i have had truble with.