E-ZPass Windshield Issues: Why Your Tag Won’t Read
Senior Automotive Glass Diagnostic Specialist & Master Technician at CarGlassFix · AGSC Master Certified Auto Glass Technician, NGA Certified Installer, I-CAR Automotive Safety Specialist · 12+ Years in Automotive Glazing, Windshield Structural Bonding, ADAS Camera Calibration & Precision Chip Restoration
An E-ZPass tag fails to read through a windshield when it sits in the wrong spot or when the glass has a metal-based infrared-reflective, solar or heating layer that blocks radio signals. Many coated windshields have a marked uncoated window, often a shaded patch beside the rearview mirror. Without a usable window, agencies issue an exterior license-plate tag.
Why some windshields block E-ZPass tags
A windshield blocks an E-ZPass tag when the glass carries a thin metal-based coating or a heating layer between the tag and the toll antenna. The tag works by radio. Polestar’s manual describes the exchange: at a toll station, the transponder receives a signal and sends back an identification number. A conductive layer in the glass weakens that exchange or stops it.
Glass maker Saint-Gobain states in a 2018 patent that many metal-containing coatings reflect radio-frequency radiation. Mercedes-Benz writes in its 2025 GLE manual that the infrared-reflective coating “shields the vehicle interior from radio waves.”
The Indiana Toll Road lists coatings known as Solar Ray, Solar Tint, heat-reflected, Insulated and Insta-Clear. It says the colored tint band along the top of the glass should have little to no effect. Our guide to heat insulating (solar) glass in a car covers how coated glass keeps heat out.
| Glass feature | What it is | Effect on the tag | Source |
|---|---|---|---|
| Infrared-reflective or solar-control coating | A clear metal-based layer that reflects heat | Blocks the signal outside the uncoated window | Mercedes-Benz, Polestar |
| Heated windshield | Heating elements or a heated coating in the glass | Can stop reads; some cars leave a corner free of heating elements | SunPass, Indiana Toll Road |
| Insta-Clear | A heated-windshield name used on toll agencies' vehicle lists | Bumper tag on listed models | E-ZPass Virginia, NJ E-ZPass, SunPass, Indiana Toll Road |
| Metal-based window film | Aftermarket film that contains metal | Polestar warns against metal film in front of the tag | Polestar |
| Colored tint band | The shade band along the top edge | Little to no effect | Indiana Toll Road |
Which cars have a toll-blocking windshield
Cars with infrared-reflective or heated windshields are the ones that need a special tag position or an exterior tag. Toll-agency lists name luxury models from brands such as BMW, Mercedes-Benz, Jaguar, Land Rover, Lincoln, Porsche and Tesla, plus older GM and Ford vehicles. E-ZPass Virginia warns that other vehicles may have the same glass without appearing on its list.
| Vehicle | Glass | Where the tag goes | Source |
|---|---|---|---|
| 2025 Ford Expedition, Lincoln Navigator, Lincoln Nautilus | Coating that Ford calls a UV coating | Uncoated shaded area in front of the mirror, next to the camera console | Ford SSM 53842 |
| Tesla Model S (2012 to 2020 manual) | Metallic coating | Cut-out right of the mirror on most cars; rear window or front-plate tag without it | Tesla owner’s manual |
| Mercedes-Benz GLE (2025) | Infrared-reflective | Only the marked areas, one by the mirror and one at the bottom center | Mercedes-Benz manual |
| Polestar 3 (2025) | Infrared-reflective | Right of the overhead console, or bottom left or right of center | Polestar manual |
| BMW 7 Series, 2009 to 2020 | Special coated glass | Top center, in the black shading | SunPass |
| Lincoln Navigator 2018 to 2020, Continental 2017 to 2020 | Special coated glass | Top left of the mirror module, in the black shading | SunPass |
| Range Rover 2010 to 2020, Discovery 2017 to 2020 | Heated | Bottom-left corner, beyond the heating elements | SunPass |
The lists do not always agree. Tesla’s manual says most Model S cars have a cut-out, and SunPass requires a bumper tag only on 2012 to 2016 nose-cone cars. The Indiana Toll Road lists a bumper tag for every Model S and Model X. A Kapsch list posted by E-ZPass Maryland says the Model 3, S, X and Y need an exterior tag. That list also flags Low E glass, automatic sensing wipers and Mercedes Night View Assist.
How to find the uncoated window on your windshield
The uncoated window is a marked patch of glass, usually near the rearview mirror, and the owner’s manual shows where it is. Ford, Mercedes-Benz, Polestar and Tesla each describe the window in their own documents. The steps below combine their instructions with the agency lists.
How to find the toll-tag window and mount the tag in it
Read the owner’s manual
Look for a section on toll transponders, RFID or radio waves. Ford added a picture of the shaded area to the online manual for the 2025 Expedition, Navigator and Nautilus.
Check your toll agency’s list
SunPass, the Indiana Toll Road, NJ E-ZPass, E-ZPass Virginia and E-ZPass Maryland publish lists of special windshields and tag positions.
Find the marked patch on the glass
SunPass places many windows in the black shading near the mirror. Mercedes-Benz says the areas show best from outside the car with a light shining on the glass.
Mount the tag inside the window
Follow the tag maker’s orientation. Ford says many tags still work when most of the tag, and the RFID transmitter inside it, sit in the shaded area.
Test and adjust
Check the account after a few tolled trips. Ford tells owners to move the tag within the shaded area until reads are consistent.
Ask for an exterior tag if reads still fail
Call the toll agency if no window exists or the tag keeps missing reads.
Keep the window clear once the tag is in place. Only one tag belongs on the glass. TxDOT says a second toll tag can interfere with the first or lead to a double charge. On the 2025 Expedition, the window sits right next to the camera console. Our guide on how to tell if your windshield has a camera shows what that housing looks like.
Black dots and the tint band: where the tag goes on normal glass
On a windshield without a coating, the tag goes high on the glass behind the mirror, below the tint band and the black dots. The New York State Thruway asks for at least 1 inch to the right of the mirror’s center support and at least 1 inch below the tinted section. The PA Turnpike says to mount the transponder horizontally under the mirror, below shaded or black-dot areas. On coated glass the advice can reverse, because the uncoated window often sits inside a shaded patch.
| Agency | Placement rule |
|---|---|
| NYS Thruway (E-ZPass NY) | At least 1 in right of the mirror’s center support and 1 in below the tinted section; label facing you, arrows up |
| E-ZPass Delaware | At least 1 in right of the mirror’s center support and 1 in below the roofline |
| Indiana Toll Road | Behind the mirror, about 1 in down from where the roof meets the windshield |
| PA Turnpike | Horizontally under the mirror, below shaded or black-dot areas |
| MTA Bridges and Tunnels | Middle of the windshield, just below the mirror mount |
| EZDriveMA | Just right of the mirror arm, below any tinting, arrows up |
| TxDOT (TxTag) | Behind the mirror, at least 4 in from the top edge |
| Bay Area FasTrak | Above or right of the mirror; lower left or right corner as a backup |
The rules differ by a few inches, so follow the sheet that came with your tag. TxDOT keeps its sticker tags at least 4 inches from the top edge because nearby metal can interfere. For inspection stickers, permits and the printed marks on the glass, see what is the sticker on my windshield.
When you need an exterior or license-plate tag
An exterior tag is the fix when the windshield has no usable window or the maker’s window is far from the top center. A Kapsch list posted by E-ZPass Maryland recommends an interior tag only when the automaker’s location is near the top center. Otherwise, Kapsch recommends an exterior transponder. Bay Area FasTrak adds metal oxide windshields, flat vertical windshields, and metal visors or racks over the glass.
Exterior tags bolt to the front license plate. FasTrak supplies tamper-resistant screws and a matching wrench, and the tag goes above or below the plate. SunPass supplies a bumper-mount kit but does not install it. A car with no front-plate bracket may need changes first, SunPass says. Tesla’s Model S manual also allows a weather-proof transponder on the front plate.
In the Bay Area, FasTrak’s exterior tag has no carpool switch, so it gets no express-lane discounts. E-ZPass Virginia calls its version a License Plate Tag.
What a misread tag costs
A tag that is not read can cost more than the E-ZPass rate, even when the account is in good standing. At Port Authority bridges and tunnels, NY and NJ E-ZPass customers whose tags are not mounted for accurate reads pay a mid-tier rate. The Port Authority started the tier on July 6, 2025, and says it affects 9% of transactions. The extra charge covers the license plate photo and the account check.
| Port Authority car toll, July 2026 (eastbound) | Rate |
|---|---|
| E-ZPass, off-peak | $14.79 |
| E-ZPass, peak | $16.79 |
| Mid-tier (NY or NJ E-ZPass tag not read) | $19.55 |
| Tolls by Mail | $23.30 |
MTA Bridges and Tunnels introduced a mid-tier rate for improperly mounted New York Service Center tags on April 11, 2021. The PA Turnpike matches a missed read to the license plate on the account. A missing or outdated plate can bring a Toll By Plate invoice at a higher rate. The PA Turnpike says properly mounted transponders read with 99.5% accuracy. The Indiana Toll Road’s mounting sheet lists a $1.00 surcharge, from May 1, 2012, when an improperly mounted tag needs customer-service help.
What to do after a windshield replacement
After a windshield replacement, confirm that the new glass has the same transponder window as the old one, then remount or replace the tag. Saint-Gobain’s patent describes one way to make it: a laser cuts gridlines into the coating before the glass is bent. Tesla says whether a Model S has the cut-out depends on its date of manufacture.
- Hard-case E-ZPass tags: remount the tag with new strips. E-ZPass NY customers order them in the TOLLS NY app or online account.
- Sticker tags: order a new one. CFX and THEA say E-PASS and SunPass Mini stickers stop working once removed. TxDOT says removal can damage a TxTag chip.
- Coated glass without a window: ask the toll agency for an exterior tag.
Compare OEM vs aftermarket glass before the job, and ask the shop to show the window on the new part. Heated glass has its own steps in how to replace a heated windshield. For old sticker glue, see how to remove adhesive from a windshield. If the car has a windshield camera, read how sensors are calibrated after windshield replacement.
Frequently asked questions
Does E-ZPass have to be on the windshield?
An interior tag does. The New York State Thruway says not to hold the tag or put it on the dashboard, and Bay Area FasTrak says holding up a tag at a toll plaza is illegal. Cars that cannot use an interior tag get an exterior tag on the front plate.
Does window tint block E-ZPass?
The colored tint band along the top of the windshield should have little to no effect, according to the Indiana Toll Road. Polestar warns against metal film in front of the transponder. Read does windshield tint interfere with sensors for film types.
Why won’t my E-ZPass stick to the windshield?
Clean the glass with isopropyl alcohol and let it dry, as Bay Area FasTrak directs. TxDOT says the glass must be above 50°F for its sticker adhesive to hold. E-ZPass NY customers can order new strips in the TOLLS NY app.
Who should I call if my tag is still not read?
Call the agency that issued the tag, such as NJ E-ZPass, E-ZPass Virginia, SunPass or Bay Area FasTrak. The customer service number is on the agency's website and on your statement, and the agency can tell you whether your car needs an exterior tag.
Sources
- Ford Special Service Message 53842: 2025 Expedition, Navigator and Nautilus windshield RFID transponder placement (NHTSA, May 2025)
- Tesla Model S owner’s manual: using RFID transponders
- Mercedes-Benz 2025 GLE operator’s manual, pages 159 and 160
- Polestar 3 manual (2025): road toll transponders
- Saint-Gobain Glass France, US patent 9,873,169 B2: coated pane with partially de-coated regions (2018)
- SunPass: windshield installation and special windshields (checked 24 October 2026)
- Indiana Toll Road: transponder mounting procedure and vehicle list
- E-ZPass Maryland: vehicles potentially requiring external transponders (Kapsch list, July 2025)
- E-ZPass Virginia: special vehicle listing
- NJ E-ZPass: vehicles requiring exterior tags (checked 24 October 2026)
- Bay Area FasTrak: choosing and mounting a toll tag
- New York State Thruway: mount your E-ZPass tag
- E-ZPass Delaware: how to mount your transponder
- PA Turnpike: the top E-ZPass mistakes drivers make (January 13, 2026)
- MTA: new mid-tier toll rate for E-ZPass users not using their tags properly (April 2021)
- Port Authority of New York and New Jersey: toll rates (July 2026 rates, checked 24 October 2026)
- EZDriveMA: transponder information
- TxDOT: how toll tags work
- Central Florida Expressway Authority: E-PASS installation
- Tampa Hillsborough Expressway Authority: how to install a SunPass transponder
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