I would highly recommend Vinylex by Lexol. It goes both ways. Spray on a rag, wipe the dash and any plastic, flip rag, buff off. If you just wipe and leave it Vinylex will leave a wet look, if you buff off it will leave a patina. The color will deepen, but it wont be shiny given some buffing. Tip: after your done with the dash take a paper towel with some Windex/glass cleaner and clean the bottom of your windshield. It is quite easy to get some Vinylex on the bottom of the windshield when applying to the dash.

Hope this helps...Lee