Testor's Dullcoat will go a long way toward toning down shine--possibly too far--because older car paints (I-step) tended to dull more than modern ones (2-step) do. Experiment on a cheapie first, and be sure to mask the glass!!
Repainting people is absolutely possible! There are whole organizations devoted to figure painting, often associated with military figures. Some of the techniques won't work on most of our figures because they rely on much more finely sculpted texture than our figures enjoy. Still, other techniques are certainly usable to make the stuff sold for our RRs better looking.
