ive seen rs (4 spoke) alloys on mk2 xr2's. i know the off sets are different as there for rwd cars.

do i need smaller tyres if i put them on a fiesta?

 

The Mk1 Fiesta Supersport came on 4 spoke RS wheels - They should be a suitable offset.

 

I ran 7j 4 spokes on mine, then later 7j RS7's. If they are only the 6j and rwd offset they fit but look like they are fitted with spacers and imo look wrong.
The supersport fwd offset will be getting rare i imagine.