At home I can park my truck east or west. Yes, interior is hotter if the truck is facing west in the afternoon.
In years past I have triad other things, with little success, even using a reflective Mylar on the exterior of the windshield.
Where have you been ? I have been doing that for years plus the windshied sun shade .
Additionally, it affects one’s tire pressure. I have noted an increase of 1-2 psi on the tires that are directly facing the summer sun.
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Egads, don’t mention tire pressure!
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That was two I’s meaning one person, and then a whole lot of we’s and us’s (yes I know that is bad English lol) meaning a group of people, are we talking to one person, the same person, or will there be multiple users using your Avatar/account??
I get the We have never seen–, but we will erase-- means multiple users…
Simple question, we just like to know who/what we are dealing with…lol
I made a mistake once, a couple decades or so ago, for a course on atmospheric physics (taken purely for fun), by generalizing from an EPA publication which discussed urban heat islands - a concept which applies well to cities in valleys which create somewhat isolated microclimates, when the cross-region windspeed is low. I wanted to claim we could stop global warming and maybe eliminate smog by using light colored roads and rooftops, which would reflect more light and reduce A/C electric loads. But even a crude quick calculation showed that there wasn’t enough road and rooftop area to affect the whole planet much, because most parts of the planet have low population density. So I claimed we could modify urban climate that way, which I argued relevant because most people live around cities. But of course it did not apply very well to areas like around Washington, DC, which is in the middle of a large semi-flat plain, the “Piedmont Plateau”, so we normally have winds that sweep across large portions of that region. DC almost never has real smog, though it is true we can normally no longer see the Blue Ridge Mountains from D.C.
Much of Texas is in a plateau too.
Super-white road and roof covers might reduce temperatures in very high population density areas, but I bet it would be hard to affect the climate much of most of the Piedmont Plateau or Texas. (Reducing individual home A/C electricity use is more practical. There have always been a lot of light rooftop surfaces on homes close to the equator, especially in 3rd world countries. And most vanlifers, overlanders, and maybe motor home buyers, prefer white vehicles. Someone in a vanlife forum said they built a cheap evaporative cooling system which kept the moist air outside, and used a home-made heat exchanger to cool the inside, without adding much internal humidity, or using much electricity.)
Anyway, it sounds like their paint is just very reflective in the visible and near infrared, but emits (which according to thermodynamics also means absorbs) a lot in the far infrared, so it radiates the heat away.
Pretty simple idea. Not entirely new:
The whitest paint is here – and it’s the coolest. Literally. - Purdue University News
https://www.texcote.com/reflect-tec/reflect-tec-colors
I guess a lot of engineering consists of finding economically more practical ways to make simple ideas work. If Nissan has done this, that’s great! But as you folks pointed out, repainting my car still isn’t worth it. 
Since you are interested in climate change, it may interest you that in the 1950s the USDA studied modifying the climate and ecology of the High Sierras to incorporate more water. I think it was dropped because the U.S. signed a treaty barring engineering large scale climate modification. I don’t know the details. They and others have worked a lot on stabilizing sand dunes, and reducing agricultural erosion, such as contributed to the American Dust Bowl era. Many farmers use local climate modification - e.g., places where windbreaks extend the lifetime of winter snow for irrigation. The EPA publication I mentioned said that in former times, transpiration from center-city orchards helped keep cities cooler in the summer. There have also been a lot of studies of how the development of Columbia, MD has affected its climate.
But none of this is relevant to my car.
The brush painting I did looks a heckuva lot better than the dozen cans of Duplicolor I have put on over the years. Water beads up on it! It stays in the flexible parts. I responded to OP, who wants to keep his car cooler. He didn’t mention how it looks. @George_San_Jose1 has cars even older than mine - does he care more about the look than the protection?
I’m marking the reply that first cited $5000 to do a good job of repainting the car (which is too expensive for me) as having solved the problem.
I.E., I don’t need any more replies about this. Since painting is economically practical, I am using a variety of other solutions.
Just want to point out one thing. Interior window shades do not keep the interior of the car cooler. About the only help they give is to keep the steering wheel from becoming too hot to handle, especially if it is a black steering wheel.
An exterior sun shield on the windshield is a lot more effective, but then it is easily stolen. One solution is to make your own shield out of cardboard that covers your windshield with wings to stick into the front doors to hold it in place. Too cheap to steal, custom made, very effective.
You could also make one out of an old bed sheet or any large piece of cloth.
Do not use a reflective tint on your windows, they can blind other drivers. Reflected sunlight is far brighter that the brightest headlights available today.
I disagree. Put one of these inside behind the windshield, much cooler when I get back to the car:
hmmm …???.. I’m not seeing that. No doubt that putting a reflecting surface on the outside of the glass will cool the interior better than putting it inside the glass, but it seems a reflecting surface inside the glass would still be better than nothing.