That link is out of date. Try
here for the IWFA site.
Here's the link to the text of the law posted below.
26708. (a) (1) No person shall drive any motor vehicle with any object or material placed, displayed, installed, affixed, or applied upon the windshield or side or rear windows.
(2) No person shall drive any motor vehicle with any object or material placed, displayed, installed, affixed, or applied in or upon the vehicle which obstructs or reduces the driver's clear view through the windshield or side windows.
(3) This subdivision applies to a person driving a motor vehicle with the driver's clear vision through the windshield, or side or rear windows, obstructed by snow or ice.
(b) This section does not apply to any of the following:
(1) Rearview mirrors.
(2) Adjustable nontransparent sunvisors which are mounted forward of the side windows and are not attached to the glass.
(3) Signs, stickers, or other materials which are displayed in a 7-inch square in the lower corner of the windshield farthest removed from the driver, signs, stickers, or other materials which are displayed in a 7-inch square in the lower corner of the rear window farthest removed from the driver, or signs, stickers, or other materials which are displayed in a 5-inch square in the lower corner of the windshield nearest the driver.
(4) Side windows which are to the rear of the driver.
(5) Direction, destination, or termini signs upon a passenger common carrier motor vehicle or a schoolbus, if those signs do not interfere with the driver's clear view of approaching traffic.
(6) Rear window wiper motor.
(7) Rear trunk lid handle or hinges.
(8) The rear window or windows, when the motor vehicle is equipped with outside mirrors on both the left- and right-hand sides of the vehicle that are so located as to reflect to the driver a view of the highway through each mirror for a distance of at least 200 feet to the rear of the vehicle.
(9) A clear, transparent lens affixed to the side window opposite the driver on a vehicle greater than 80 inches in width and which occupies an area not exceeding 50 square inches of the lowest corner toward the rear of that window and which provides the driver with a wide-angle view through the lens.
(10) Sun screening devices meeting the requirements of Section 26708.2 installed on the side windows on either side of the vehicle's front seat, if the driver or a passenger in the front seat has in his or her possession a letter or other document signed by a licensed physician and surgeon certifying that the person must be shaded from the sun due to a medical condition, or has in his or her possession
a letter or other document signed by a licensed optometrist certifying that the person must be shaded from the sun due to a visual condition. The devices authorized by this paragraph shall not be used during darkness.
(11) An electronic communication device affixed to the center uppermost portion of the interior of a windshield within an area that is not greater than 5 inches square, if the device provides either of the following:
(A) The capability for enforcement facilities of the Department of the California Highway Patrol to communicate with a vehicle equipped with the device.
(B) The capability for electronic toll and traffic management on public or private roads or facilities.
© Notwithstanding subdivision (a), transparent material may be installed, affixed, or applied to the topmost portion of the windshield if the following conditions apply:
(1) The bottom edge of the material is at least 29 inches above the undepressed driver's seat when measured from a point 5 inches in front of the bottom of the backrest with the driver's seat in its rearmost and lowermost position with the vehicle on a level surface.
(2) The material is not red or amber in color.
(3) There is no opaque lettering on the material and any other lettering does not affect primary colors or distort vision through the windshield.
(4) The material does not reflect sunlight or headlight glare into the eyes of occupants of oncoming or following vehicles to any greater extent than the windshield without the material.
(d) Notwithstanding subdivision (a), clear, colorless, and transparent material may be installed, affixed, or applied to the front side windows, located to the immediate left and right of the front seat if the following conditions are met:
(1) The material has a minimum visible light transmittance of 88 percent.
(2) The window glazing with the material applied meets all requirements of Federal Motor Vehicle Safety Standard No. 205 (49 C.F.R. 571.205), including the specified minimum light transmittance of 70 percent and the abrasion resistance of AS-14 glazing, as specified in that federal standard.
(3) The material is designed and manufactured to enhance the ability of the existing window glass to block the sun's harmful ultraviolet A rays.
(4) The driver has in his or her possession, or within the vehicle, a certificate signed by the installing company certifying that the windows with the material installed meet the requirements of this subdivision and identifies the installing company and the material's manufacturer by full name and street address, or, if the
material was installed by the vehicle owner, a certificate signed by the material's manufacturer certifying that the windows with the material installed according to manufacturer's instructions meets the requirements of this subdivision and identifies the material's manufacturer by full name and street address.
(5) If the material described in this subdivision tears or bubbles, or is otherwise worn to prohibit clear vision, it shall be removed or replaced.
26708.2. Sun screening devices permitted by paragraph (10) of subdivision (b) of Section 26708 shall meet the following requirements:
(a) The devices shall be held in place by means allowing ready removal from the window area, such as a frame, a rigid material with temporary fasteners, or a flexible roller shade.
(b) Devices utilizing transparent material shall be green, gray, or a neutral smoke in color and shall have a luminous transmittance of not less than 35 percent.
© Devices utilizing nontransparent louvers or other alternating patterns of opaque and open sections shall have an essentially uniform pattern over the entire surface, except for framing and supports. At least 35 percent of the device area shall be open and no individual louver or opaque section shall have a projected vertical dimension exceeding 3/16 inch.
(d) The devices shall not have a reflective quality exceeding 35 percent on either the inner or outer surface.
26708.5. (a) No person shall place, install, affix, or apply any transparent material upon the windshield, or side or rear windows, of any motor vehicle if the material alters the color or reduces the light transmittance of the windshield or side or rear windows, except as provided in subdivision (b), ©, or (d) of Section 26708.
(b) Tinted safety glass may be installed in a vehicle if (1) the glass complies with motor vehicle safety standards of the United States Department of Transportation for safety glazing materials, and (2) the glass is installed in a location permitted by those
standards for the particular type of glass used.
So, technically, tints can be pretty easily used to generate equipment violations. If you aren't in possession of a compliance document, there's a potential ticket right there.
The law specifically says the factory tint on the front windows must comply with the 70% standard, and any additional film must transmit at least 88% of available light. That's why they say tint on the front windows is illegal. It will be hard to comply with this law with any film applied.
