So I finally got around to trying the 1Z cockpit premium, and I have definitely found my new dash treatment. It left no shine at all on my TSX dash, it's exactly the look that I was shooting for.
I also picked up some 303 and really like the way that looks on my integra dash. That plastic isn't a flat finish; it has some sheen to it naturally. Therefore I figure it'd be a waste of the 1Z since I won't ever be able to get a completely no-shine finish. Since I can get the 303 locally, I'll use that on my Integra and some of the interior plastic of the TSX where a mild sheen from the 303 doesn't bother me.
Thanks for all of the suggestions everyone,
John