I think with the Evo already being a donator vehicle, and probably one of the more popular ones, providing one, unmarked or otherwise, to RPU could upset a few of the donators, although I cant speak for everyone, so perhaps a bit of a poll could be taken on that.
If that was to be done, I'd imagine there would need to be an alternative vehicle provided to the donators to replace the Evo.
But that's just my opinion!