here is the reference...its a long one
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
(B) The capability for electronic toll and traffic management on public
or private roads or facilities.
(c) Notwithstanding subdivision (a), transparent material may be installed,
affixed, or applied to the topmost portion of the windshield if the following
(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
(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
Amended Sec. 77, Ch. 1154, Stats. 1996. Effective September 30, 1996.
Amended Sec. 1, Ch. 476, Stats. 1998. Effective January 1, 1999.
26708.2. Sun screening devices permitted by paragraph (10) of
subdivision (b) of Section 26708 shall meet the following
(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.
(c) 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 (c) 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.