it depends which cossie rims you are after, i have seen escort 17" cossie rims on a fiesta b4, which looked good, but u av got to take into account the width of the wheels aswell as the diameter, because i had to fit spacers on my wheels on my car and they are only 195mm wide, getting wide rims will cause them to rub on the inside of the arch or on the dampers. so appropriate spacing is needed, and a fair bit of arsing around with the arches would be needed, it all depends what u want to go for!