Will installing ETC on the black dotted area of the windshield affect its usage?

[DeJulian]

The ETC device can be installed on the black dotted area of the windshield, as long as it does not obstruct the driver's view and can detect the toll station's scanning equipment. However, installing it on the black dotted area also has drawbacks, such as reduced solar charging capability, which may lead to power depletion over time. For small vehicles, the ETC is generally installed on the upper middle part of the windshield, while for large vehicles like trucks and buses, it is installed on the lower middle part. The suitable installation position should be no lower than 1.2 meters and no higher than 2.5 meters, with an installation angle between 30 to 90 degrees. If the vehicle has anti-explosion film or if it is applied later, it may affect the signal transmission of the microwave communication link, so it should be installed on the microwave window strip. Here are some precautions for ETC installation: Do not obstruct the view; it's best to install it behind the rearview mirror: Many car models have windshields with a large backward tilt angle, which can reduce the driver's field of vision. If this is not considered during ETC installation, it may increase the driver's blind spot. Installing it on the right side behind the rearview mirror can help avoid obstructing the view. Do not affect charging: The ETC electronic tag consumes power, but generally does not require charging or battery replacement because it has a solar panel on the back for self-charging. Therefore, during installation, avoid the black dotted area on the windshield and positions that may block the solar panel. Once installed, do not remove it arbitrarily: The button in the middle of the adhesive is an anti-removal rod connected to a switch. After the electronic tag is installed, the windshield will press the anti-removal rod in. If the tag is removed arbitrarily, the rod will pop out and trigger the switch, locking the electronic tag and rendering it unusable. You will then need to visit an ETC service point to unlock it. This is designed to prevent multiple vehicles from sharing one device. When using ETC, note the following: The ETC transaction sensing range is 8 meters. To avoid issues caused by the ETC device of the vehicle in front malfunctioning, maintain a distance of more than 10 meters from the vehicle ahead to prevent automatic payment for the preceding vehicle. The ETC lane recognizes vehicle speeds of up to 20 km/h; driving too fast may result in failure to read the vehicle's device information, leading to payment failure. When using a debit card linked to ETC, insufficient balance may also cause payment failure.

[SanCali]

I specifically asked the ETC installation technician last time, and he said the black area is called the metallic glaze layer, which is sprayed onto the car glass during manufacturing. This layer actually contains trace amounts of metal, like an invisible metal mesh. When you stick the ETC device there, part of the signal gets blocked during transmission—similar to how your phone signal weakens in an elevator. I personally tried mounting it slightly to the left, and the high-speed toll machine recognized it with a 'beep' from far away without any issues. I remember one time I stuck it too high up, and the adhesive softened under direct sunlight, causing the device to fall onto the dashboard. So there's really no need to take the risk—mounting it below the black area is the safest choice.

[CarsonMarie]

Personal testing confirms that installing ETC in the black area does affect performance. Last time I drove a friend's car on the highway, his ETC was stuck right in the middle of the black dot area, and we had to reverse and adjust position at every toll gate. Later, I helped peel it off and reattach it to the clear area behind the rearview mirror. Surprisingly, the car that used to crawl through toll gates now breezes through at 30 km/h directly. Old Wang from the repair shop told me the black grid absorbs radio waves, especially with worse signal attenuation on rainy days. Now when installing ETC, I always advise car owners to avoid this area. The spot to the right of the rearview mirror is both discreet and doesn't obstruct vision—mine's worked flawlessly for three years there.

[JourneyLynn]

The black area on the windshield is a sunshade layer that appears ordinary but contains special metal oxides. Placing the ETC device here is like putting armor on the signal—the receiver can receive it, but the transmitted signal gets weakened. When passing through the highway, the device needs to continuously send encrypted data. If the signal is too weak, card reading may fail. A friend once experienced three failed card readings due to incorrect placement, ultimately having to queue in the manual lane. Nowadays, newly released ETC devices are less sensitive to placement, but it's still better to avoid the black spots if possible. If you must place it there, it's recommended to test drive first, ensuring successful gate passes repeatedly before fixing it in place.