Why Chinese cars have unique tinted window cutouts
Most cars in China have tinted windows. However, an open space is left near the mirror for several reasons.
Each country has its customs. Residents of China usually do not significantly modify the exterior of their cars, mainly due to strict regulations. They focus on personalizing the interior and tinting the windows, but they do it in their own way.
A Reddit user, ReeiTheModerator, explained the issue of "trimmed" tinting in more detail: "Cutouts are introduced for legal reasons." After registering the car, you can fully tint the window, but it requires a lot of "paperwork," there is still a chance that such a solution won't pass the annual inspection. So, the solution is to cut out a piece near the mirror so you can keep driving the car.
Another user (who decided not to go with such tinting) also noted that many parking lots in China are underground, making manoeuvring with darkened windows difficult – unless you open them completely.
It's worth noting that China has no tint limit for front windows. In the UK, the front windshield must allow at least 75% of light in, and the front side windows must allow at least 70% of light through, making such tinting impossible.
