Can ETC be attached to the black dots?
4 Answers
The ETC device can be installed on the black dots of the windshield, as long as it does not obstruct the driver's view and can sense the detection equipment of the toll station. However, installing it on the black dots of the windshield also has drawbacks, namely that the solar charging capability of the ETC device is weakened, and over time, it may run out of power. The installation position for small car ETC is generally in the upper middle part of the front windshield, while for large vehicles like trucks and buses, the installation position is in 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 and 90 degrees. For vehicles with factory-installed or aftermarket explosion-proof film, which may affect the signal transmission of the microwave communication link, the ETC should be installed in the microwave window strip. Here are the precautions for installing ETC: Do not obstruct the view; it is best to install it behind the rearview mirror: Many car models have windshields with a large rearward tilt angle, which reduces the driver's field of vision. If this is not considered when installing the ETC, it will increase the driver's blind spots. Installing it behind the rearview mirror on the right side can avoid obstructing the view. Do not affect charging: The ETC electronic tag consumes power, but generally, it does not need to be charged or have its battery replaced because it has a solar panel on the back that can charge itself. Therefore, during installation, avoid the black areas on the windshield and positions that may easily block the solar panel. Once installed, do not remove it casually: The button in the middle of the adhesive is an anti-removal rod connected to a switch below. After the electronic tag is installed, the windshield will press the anti-removal rod in. If the tag is removed casually, the anti-removal rod will pop out and trigger the switch, locking the electronic tag and rendering it unusable. You will then need to go to 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 prevent the ETC device of the vehicle in front from malfunctioning, maintain a distance of more than 10 meters from the vehicle in front to avoid automatic sensing and paying for the vehicle in front. The recognition speed for ETC lanes is 20 kilometers per hour. Driving too fast may result in failure to read the vehicle device information and cause payment failure. When using a debit card bound to ETC, insufficient balance will also cause payment failure.
I made this mistake when installing my ETC device. Thinking the black dotted area was a good spot to hide the device, I applied adhesive there to secure it, only for it to loosen and fall off within days. Later, a mechanic friend explained that those black dots are ceramic frits on the windshield, featuring tiny bumps and irregular textures that significantly reduce adhesive strength, making it easier for dust and grime to cause detachment. The correct method is to choose a smooth, dot-free area nearby, such as clean glass around the rearview mirror, wipe it with alcohol, then press firmly for a secure bond. Sticking it on the black dots not only affects ETC signal reception but may also cause malfunctions at toll stations, leading to extra charges. That’s why I always remind people to avoid the black dots when helping them install ETC devices—this tip has saved me a lot of trouble. Remember to check the adhesive strength regularly.
As someone who frequently tinkers with in-car devices, I understand that sticking the ETC on the black dots is indeed not advisable. The black dot area isn't flat glass but rather a ceramic sintered dot matrix designed to block sun glare and dissipate heat. Its irregular surface prevents adhesive from sticking firmly, and strong vehicle vibrations may cause it to slip, leading to device malfunction. I've tried cleaning and reattaching it, but the results were unsatisfactory. In actual installation, you should choose a smooth section of the windshield, preferably the upper center on the driver's side, ensuring it doesn't obstruct the view. Before installation, make sure the glass is free of grease and use professional adhesive, pressing firmly for at least one minute. Neglecting this small detail might leave you embarrassingly stuck at a toll booth. That's why I always teach people this simple method: feel the glass to find a completely smooth area, stick it firmly, and ensure the device remains stable—it's a crucial step for driving safety.
I think the ETC shouldn't be stuck on the black dots, as they weren't designed for adhesion in the first place. The black dots are decorative spots on the glass, somewhat rough, making it hard for the adhesive to grip firmly. After installation, it might fall off or become loose within a few months. Based on my experience, it's best to place it on the smooth glass area near the center rearview mirror. Clean the spot with some alcohol, let it dry, and then press the adhesive tape firmly. This location offers strong signal reception and minimal obstruction to your view. Don't underestimate this issue—if the ETC isn't securely attached and starts beeping randomly during your trip, you might end up paying unnecessary fees. Ensuring the surface is clean and flat when fixing the device is a must.
