Good news... I tested a super black super matte acrylic paint... and it works to cut the glare and reflection on your windshield of your dashboard

When I learned of Vanta Black, I knew right away what I wanted to try it on... but they don't sell Vanta Black. They sell something a bit less light absorbing: Stuart Semple Black 2.0, it's acrylic.
https://www.amazon.com/gp/product/B0758GKKGZ/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1  and it costs 20 dollars for 2/3rds of a cup. No, that's not a good price. It's not as effective and incredible as they claim, and the publicity photos they use to promote it are in low indoor light, making it seem darker.

here you can see the construction paper I painted with it to cover the dash, and it's certainly not shiny, but 10 percent as light absorbing as they make it seem

So... there you have it. a 24 dollar experiment to reduce windshield glare.