--- title: "Is a windshield sun strip legal in California?" url: "https://maviautoglass.com/blog/is-a-windshield-sun-strip-legal-in-california/" description: "California Vehicle Code 26708 sets a 29-inch seat measurement, not a 4-inch rule, for a windshield sun strip. How to measure it on your car" content_signal: ai-train=yes, search=yes, ai-input=yes --- # Is a windshield sun strip legal in California? California Vehicle Code 26708 sets a 29-inch seat measurement, not a 4-inch rule, for a windshield sun strip. How to measure it on your car A windshield sun strip is legal in California if it sits on the topmost portion of the glass and its bottom edge is at least 29 inches above the driver’s seat, measured the way Vehicle Code section 26708(c) describes. The strip must also be transparent, not red or amber, without opaque lettering, and must not reflect more sunlight or headlight glare than the bare windshield. The law does not say “4 inches” and does not use the AS-1 mark as the limit. Those are shortcuts that tint shops use, and the real limit depends on your vehicle’s seat and windshield. Many pages, and even some search summaries, repeat the 4-inch rule as if it were the law, so the difference matters. This guide is written by Mavi Auto Glass, a locally owned mobile auto glass company based in Roseville that replaces windshields for drivers across Sacramento, Rocklin, Folsom and the rest of Greater Sacramento. It quotes the current text of section 26708, which was last amended by Senate Bill 506 effective January 1, 2026, and shows how to measure the line on your own car. It is general information, not legal advice. ## What does California Vehicle Code 26708(c) say about a sun strip? Subdivision (c) allows transparent material on the topmost portion of the windshield when four conditions are met ([Vehicle Code 26708](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=26708)). - The bottom edge of the material is at least 29 inches above the undepressed driver’s seat, measured from a point five inches in front of the bottom of the backrest, with the seat in its rearmost and lowermost position and the vehicle on a level surface. - The material is not red or amber. - There is no opaque lettering, and any other lettering does not affect primary colors or distort vision. - The material does not reflect sunlight or headlight glare into the eyes of other drivers more than the windshield would without it. ## Is the 4-inch rule for windshield tint the law in California? No. The phrase “4 inches” does not appear in section 26708, and neither does the AS-1 line as a limit for the strip. A fixed number of inches is a shortcut some shops use, but the line set by the statute depends on the seat height and the shape and angle of each windshield, so it changes from one vehicle to another. The table compares the claims you will see online with what the statute says. What you may readWhat section 26708 saysThe strip can go down 4 inchesThe bottom edge must be at least 29 inches above the driver’s seat, measured as described in (c)The AS-1 line on the glass is the legal limitThe statute uses the seat measurement, not the AS-1 markAny color works if it is lightRed and amber are not allowedClear film can cover the whole windshieldOnly with at least 88 percent light transmittance and a certificate signed by a licensed dermatologist, under subdivision (e)Mirrored strips are fineThe strip cannot reflect more glare than the bare windshield ## How do you measure the 29-inch line on your own car? You measure from the driver’s seat to the windshield using the reference point the statute gives. Here is the method in 5 steps. - **Park on level ground:** the statute requires the vehicle to be on a level surface. - **Set the seat:** move the driver’s seat to its rearmost and lowermost position, with nobody sitting on it. - **Find the reference point:** mark a point on the seat cushion five inches in front of the bottom of the backrest. - **Measure up 29 inches:** from that point, measure straight up to the windshield and mark the height on the glass with removable tape. - **Keep the strip above the mark:** the bottom edge of the material must stay at or above that line. If you have the strip installed by a shop, ask the installer to measure this way rather than by the AS-1 mark or a fixed number of inches. ## Can you put clear film on the whole windshield in California? Only in a narrow case. Subdivision (e) allows clear, colorless and transparent material on the windshield if it has a minimum visible light transmittance of 88 percent, the glazing still meets Federal Motor Vehicle Safety Standard 205, the material is designed to block ultraviolet A rays, and the driver keeps a certificate signed by a licensed dermatologist stating a medical need. The film must be removed or replaced if it tears, bubbles or wears so it prevents clear vision. ## Does a sun strip affect the driver assistance camera? It can, because the strip and the camera share the top of the windshield. On many newer vehicles the camera for lane keeping and automatic emergency braking looks through the glass near the rearview mirror, so material over that area may interfere with what it sees. Check the owner’s manual before covering the area around the camera. A sun strip applied as film stays with the old glass when the windshield is replaced, so plan to reapply it to the new windshield if you want it. Mavi Auto Glass replaces windshields and performs [ADAS static and dynamic calibration](/service/adas-static-and-dynamic-calibration/) with its own Autel equipment, in most cases in the same appointment as the [windshield replacement](/service/windshield-replacement/). ## Before you add a sun strip to your windshield Measure the 29-inch line with the seat back and down and the car on level ground. Choose a transparent material that is not red or amber and has no mirror finish, and keep it clear of the camera area behind the mirror. If you are about to replace the windshield, wait and apply the strip to the new glass after the replacement and any calibration are done.