I seeketh it. I figure it doesn't come up much, but if anybody would know, it's this crowd.
It's fairly important to me that it looks a fair bit like gold leaf, with that characteristic mottling. Not just gold, not just gold with patterns in it.
I may never actually get to the project, but I'd probably bite the bullet and figure out how to do actual gold leaf before I'd do most of the "gold" vinyl I've seen.
I've got one lead (Schein Holographics vinyl at Sign Warehouse) that looks better than average to me, but it's hard to say from pictures and I can't find any reviews.
(In case there's curiosity, the application in this case is a bicycle helmet, though I wouldn't mind doing a bit on my autox/track helmet as well. The bike helmet application is probably more forgiving of vinyl that doesn't want to do compound curves because of the area I want to cover.)