Dash mats are the only practical way to completely eliminate, or nearly completely eliminate, reflections of the surface of the dash in the windshield.
You have to get the flattest, darkest black.
They come with cut outs for the defrost vents, and you can add as many Velcro patches as you need to make them secure.
I'd rather that the dash itself was made out of some magic non-reflective stealth material, but it isn't.
If the windshield was sloped at a steeper angle, we wouldn't get reflections.
The FJ and the Jeep commander are probably the only vehicles in recent years that had an adequately steep windshield angle. And, both were discontinued after five years.