Technically you are not allowed to add any aftermarket tint to the windshield or the front side windows in California. Doesn't matter, if it's 95% or 70% VLT (visible light transmitted). You just can't add it:
That said, I'll probably do the same tinting that XBS did, which is pretty much the same thing I did for my 2012 Prius 5 years ago. Never gotten pulled over for it.
Here is the quote from that link:
"The main requirements for legal window tinting in California are:
The windshield and front driver's side and passenger's side windows cannot receive any aftermarket tinting.
If the rear window of a vehicle is tinted, the vehicle must have outside rearview mirrors on both sides.
The law prohibits any person from driving any motor vehicle with any object or material placed, displayed, installed, affixed, or applied upon the windshield or side or rear windows, with certain limited exceptions.
However, legislation signed into law effective January 1, 1999, exempts from the above prohibition specified clear, colorless, and transparent material that is installed, affixed, or applied to the front driver and passenger side windows for the specific purpose of reducing ultraviolet rays. If, as, or when this material becomes torn, bubbled or otherwise worn, it must be removed or replaced."