As far as I know they were exclusive paint jobs available for a limited period of time only. I don't *think* they'll be making a comeback, but don't quote me on that.
They came back once, due the black Friday sales for 50% off. Then i bought me the Brittish, US, and Canadian one. They were only for the Viper though.
It was a bit off a fuzz on the forum by some people, because they where mend as a limited time only sale and to put them available again made some guys somewhat angry.
So i have no idea if they might come back on another special event.