The RS3 spoiler in the middle, at its deepest point, is almost twice as deep as the S3 spoiler. I think its pitched at a higher angel also. The S3 spoiler sits flat on the boot lid but the RS3 spoiler has some tabs on it which would not allow it to sit flat on a normal saloon. Don't see any reason as to why these could not be cut off and then 3M tape used to secure one.