subysouth - correct.
Leonardo- It doesn't matter if you are using the STi Group N mounts or not (for the record we were using the Group N mounts). On the rear struts it is not possible/recommended to use 04/V8 hats/springs on 02/03/V7 struts.
I did not get a chance to see if 02/03/V7 hats would work properly on 04/V8 struts. I would think not as the design of the hat probably needs that little shoulder to properly locate it.
So as subysouth pointed out, don't mix and match rear strut/hat years.