focus rs 324mm discs fit under 16" wheels if you use std calipers with some caliper spacers and mods
Under WHICH 16" wheels though?
My mate has 330mm under his 16" MO's on his pulsar, but no way they would fit under my escos rims.
Internal size/shape of wheels vary a lot.
On my clio ive got 2 sets of wheels, one cleared my calipers with ease, the other I had to grind quite a few mm out of to get on, both are 15" wheels.