Yeah, I will keep using the black side out so it doesn't reflect the heat up onto my dashcam
I have taken temps of the interior with black side out, silver side out, and no shade up.
Silver side out is cooler than black side out, which I've already said twice in previous posts above, but who cares about reading comprehension around here...lol
Black side out was cooler than no sunshade.
With the sunshade up, either side out, the sunshade itself gets hot. Does it get hotter with black side out vs silver? Yes, but not that much difference that I've noticed. I can still grab it with my hands and fold it up.
With no sunshade, the entire dash gets hot, along with anything else that's in direct sunlight like steering wheel, front seats, center console (maybe?) All these interior parts will keep emanating heat even after you get in and turn on the AC, plus will be uncomfortable to touch or sit on.
With a sunshade with ANY COLOR OUT, it keeps all these interior parts from absorbing the heat and getting hot. When you get in they are not hot to touch or sit on.
Keep as much of the interior out of direct sunlight, or "in the shade"
Don't need physics, just common sense