Since 718S's come standard with 19's, the issue, if any, won't be the diameter of the rim, but whether or not the width, offset, and bolt pattern are a match. Is the donor car a 718 Spyder. If so, my bet is the bolt pattern is the same and it comes down to width and offset, and again my bet is they will fit assuming the offset is close. I'm sure your local dealer can provide you with those numbers if you can't find them.