Isn't it illegal to tint front door windows in California?
Yes, for all intents and purposes, it is. It is not legal to tint either the windshield (more than a strip that goes across the top of the windshield) nor is it legal to tint the driver or passenger front windows. There is no tint made that meets the criteria for the front windows in california, however if you live here (your location says you do), you will notice that plenty of people do it.
In fact, you would probably find 40-50% of "nicer cars" that are not just "cars for transportation" with tinted front windows. I have been driving since I was 16, and I am 53, and every car I have had since I was in my mid 20s, I have tinted my front windows. Sometimes you get a ticket, but not often. I would imagine that I have gotten maybe 3-4 "tint fix it" tickets from my mid 20s till now (53).
@jimtelsa My car is 20% all around, so likely way too dark for you. Its not too dark at night for me, but my car windows are tinted dark enough that you basically cant see into the car during the day when in the sun, so obviously at night, its dark. I can see just fine out of the side windows.
The windshield is 70% as I said, and it has no obvious tint to it. Authorities will normally give you a ticket for an obviously tinted windshield, but in general, wont give a window tint ticket unless they stop you for something else, or are annoyed.