I've got a set of ST170 (300mm discs) along with Mondeo Mk3 calipers on the estate - problem is trying to find wheels that fit over the calipers (16's generally do, some 15's do and some people shave a little off the edge of the caliper allowing them to fit 15's)

My friend has the mondy/st170 set up on his MK4 Fiesta too.