The first reason is simple- it reduces glare. It is like always having sunglasses ready on your car without needing to actually find your sunglasses.
Reason two is that it increases privacy and security. This is important when it comes to having valuables in your car, or if you just want to drive without anyone seeing you. The third reason is safety. The film on the window holds the glass together. This can be a game-changer for accidents to prevent the glass from breaking into a thousand pieces. Next reason is vehicle enhancement. To put it simply, it makes your car look good. Lastly, there is solar benefits of window tinting. You can protect your body from the sun and UV rays coming in through the glass and causing sunburn or cancer. This reason is also applicable to protecting the interior of your car as well. It can help prevent your interior from getting too hot. This is why the majority of the cars have their windows tinted in areas like Florida.