I originally blacked out a portion of my hood (on a white car) with Plasti-dip to try to see if that would help the glare.
The glare that I was getting was only from the sun, I don't have roof-mounted lights to worry about.
The flat/matte black helped quite a bit, even though only a portion of the hood was covered.
Fast-forward to the life-span of the Plasti-dip and it's time to upgrade -- need justified.
Plasti-dip is crap for this application, and I use 'crap' in the kindest sense of the word, it just did not last and I think the combination of direct sun exposure and underhood temperatures, which the 80 series is famous for, just killed the coating. Not the best way to use that.
So, I removed it (it's much harder than they tell you, it took 1 1/2 hours with a pressure washer to get it off), and decided that the paint underneath is now compromised. If I left it uncovered, it would deteriorate quickly.
I decided at that point to use a vinyl wrap material, a matte finish fake-carbon fiber look. It took two guys about 30 minutes to cut it and make sure no bubbles underneath, but it turned out OK and has been pretty good to date.
Concept realized, I think the next time I remove the cowl piece, I will also cover that with the same material for consistency.
Dan.