All R4s have 3 stud wheels Don't know exactly the BCD but it does not matter, there were two of them used by Renault one for the 13" wheels and the other for the 15" ones (R8, R10...). If you are looking for aftermarket wheels, you should look at those offered in the '80s for the R5 Mk1. I had been told that the wheels from 954cc and 1124cc Saxos and 106s will fit but never tried them in personal.