You know, now that I look at pictures of the two I think the V1 vs V2 might be the same rings, but with different attachment methods to the rotor hats.
V1 has the bobbins and more attachments points.
V2 has fewer attachment screws with a retaining ring on the hub side of the hat.
V1:
http://cdn.nexternal.com/bimmerworl/...PFC_DD_500.JPG
V2:
http://gtrspectuning.com/images/IMG_...rand=755685395