Window tint
 

Just bought a 2018 Acura RDX, why is the tint so light?

add your own!

I concur that the factory tint on the rear windows and rear hatch window is a little lighter than other manufacturer's OEM colored glass. You can tint all windows to match - obviously lighter % on the factory colored glass to match whatever you put on the front.

My experience with 3 different cars in CA was the same. I used the illegal grade of tint. The first grade was like hardly any difference, but legal. 2 different tint shops told me the same thing. It is rare they get anyone to request the 'legal' tint because the difference was so small. They can still apply it but the owner is responsible if caught.
I know of no one that was ever stopped.
Now, in Central CA tinting is almost a necessity. 100+ temps, sometimes for weeks at a time, demand it. And as you would expect, many have much darker tints.
In my experience, there is a balance.
First of all, if cops can not make out your face in daylight by looking throiugh the side window, they assume (and usually they are right) you have an illegal tint. It is rare they bother stopping cars for tint unless they are suspicious of the driver anyway.
Secondly, I've experienced enough 'near misses' by cars exiting driveways without looking, but more like not SEEING me approach, and I can barely see their head let alone tell if
they are even looking my way, because of heavy window. tint.
You know that feeling you get when a car is running close to you in the next lane and you notice it has a dent on that side? And you don't want to be the next one? Yeah, that same feeling. And those cars often will have dark windows as well.

Probably safety standards. Are there tint/audio shops near you? they will have an answer or have helped others in your sitch.