I have designed a conversion using the S4 Rx7 calliper working with a VW Golf rotor mounted to a 200B strut.
It was what I needed at the time.
No reason it can't be modded to suit other struts, the same basic suck it and see process will apply.
A CAD drawing is available for anyone who wants to have a look.
No Engineers certificate is supplied
No liability is accepted
I had to go to 15" alloys with this conversion.
Probably not a big issue with a 1600 [factory wheels are 13"] but may be too much for a car which started with 12" wheels.
I think there are legal issues going more than +2" in wheel diameter
Perhaps the tyre placard could turn up missing