Does ETC Have to Be Installed on the Windshield?

[AlejandroAnn]

ETC does not necessarily have to be installed on the windshield. Mounting the ETC device on the upper part of the windshield is primarily to minimize obstruction of the driver's view and to ensure better recognition by the equipment at highway toll stations. However, this is not the only installation method. Below are some considerations for ETC installation: Minimize obstruction of view, best installed behind the rearview mirror: Many car models have windshields with a steep rearward angle, which can reduce the driver's field of vision. Installing the ETC without considering this can increase blind spots. It is recommended to install the ETC behind the rearview mirror on the right side to avoid blocking the driver's view. Do not interfere with charging: The ETC electronic tag requires power but generally does not need charging or battery replacement, as it has a built-in solar panel for self-charging. Therefore, during installation, avoid the blackened areas on the windshield and positions that may block the solar panel. Do not remove the device arbitrarily once installed: The adhesive backing includes an anti-tamper rod connected to a switch. Once the ETC tag is installed on the windshield, the rod is pressed in. If the device is removed, the rod will pop out and trigger the switch, locking the tag and rendering it unusable. Unlocking requires a visit to an ETC service center. This feature prevents multiple vehicles from sharing a single device. ETC usage tips: The ETC transaction sensing range is 8 meters. To avoid issues caused by a malfunctioning ETC device in the vehicle ahead, maintain a distance of at least 10 meters to prevent accidental toll payment for the preceding vehicle. The ETC lane recognizes vehicles at speeds up to 20 km/h; exceeding this speed may result in failed transactions. Using a debit card linked to ETC with insufficient balance will also cause payment failures. ETC stands for Electronic Toll Collection, a system that allows drivers to pay tolls without stopping while driving on highways. To apply for an ETC device, visit a bank branch or highway service area. Required documents include the vehicle owner's valid ID and vehicle registration certificate (original and photocopy). If applying on behalf of the owner, the agent's valid ID is also required. The photocopy of the registration certificate should include the page with the most recent annual inspection stamp. Applicants must be aged 18 to 60 and own a vehicle. For corporate applications, the required documents include the agent's ID (or driver's license), the company's organization code certificate (or business license), and the company seal. ETC is an electronic toll collection system that enables toll payment without stopping. It uses dedicated short-range microwave communication between the vehicle's electronic tag (installed on the windshield) and the microwave antenna in the ETC lane at toll stations, with backend processing via computer networks and banks.

[McAlexa]

I don't think the ETC device must be installed on the windshield, but it's highly recommended to place it at the upper center of the windshield's inner side or behind the rearview mirror. These positions ensure the most stable signal reception, as they're designed to be securely attached with adhesive, preventing malfunctions due to vehicle vibrations. Signal transmission depends on the orientation of the device's antenna. The windshield directly faces the external environment, making it easier for high-speed toll station equipment to recognize the device, with a tested success rate as high as 99%. If installed on the dashboard or door side, the signal might be obstructed or weakened, increasing the risk of delays or failures at toll stations. Additionally, the windshield location doesn't interfere with airbag deployment zones, enhancing safety. I once tried using a magnetic mount on the dashboard for convenience, but frequent manual reboots became quite annoying. The official manual also recommends attaching it to the windshield. Cleaning the surface during installation to avoid bubbles or wrinkles ensures better adhesion and a longer lifespan.