I found the FR8DPP30X number on the box to the spark plug itself, it's printed just below the 6702. On the box though it only states the it is indeed platinum and not double platinum, guess they've made a change of what the code represents
Everything you've spoke about make perfect sense, if I would have known that the lifespan and performance was a real factor then I would have picked up the double platinums in the first place. I'm going to return these and pick up 7422 plugs.
I was thinking that the whole double platinum thing was more marketing than anything, it's good to know that its not. The +4 plugs come to mind...