I'm not sure I'd say these engines have run their course, given that they still sell for top dollar. Obviously, there's still a lot of interest in them, and in all the AEC glow-in-the-dark items. However, given that they're kind of a novelty item, I'm not sure larger scale engines and cars with that theme would be considered for production. But many of these kinds of items, including the Area 51 stuff, seemed to sell very well, and we may see more of these in the future, at least in traditional sized items.