Cleaner footage when the dashboard starts reflecting
Windshield reflections can flatten dash cam footage, especially when a glossy dashboard throws light back into the lens. This VIOFO CPL filter tackles that problem by reducing glare before it reaches the sensor, which is exactly what you want from a small optical accessory.
Because it is made for the A329S, A229 Pro, A229 Plus and compatible rear-camera setups, it fits into a very specific VIOFO ecosystem rather than acting as a generic add-on. That makes it more relevant than universal clip-on filters, but the real question is how much image quality it can recover in daily driving?
What 99.9% polarisation means on the road
The product claims a 99.9% polarising coefficient, which suggests strong control over reflected light from glass, water, and polished trim. In practice, that should mean less washed-out sky, fewer mirror-like dashboard streaks, and better contrast in bright daylight.
Users who installed it on the A329S reported that the filter made the already sharp camera look even clearer, with scenery appearing more vivid. That matches the expected behaviour of a CPL lens: it does not create detail, but it helps the camera capture the detail that glare would otherwise hide.

Magnetic mounting is the practical advantage
The magnetic adsorption design is one of the strongest reasons to choose this model. It makes installation quick and keeps the filter easy to remove when you want to clean the lens or compare footage with and without polarisation.
That matters for dash cam owners who switch vehicles or adjust their setup often, because a fiddly twist-on filter can become annoying over time. Here, the attachment method feels more like a convenience feature than a gimmick, and that is useful in a product meant for everyday driving.
How it changes the look of your recordings
This filter is aimed at making recordings look more natural rather than more dramatic, although the sky and cloud contrast can improve when light is polarised correctly. The result is usually a cleaner, more usable image for incident review, number plate checks, and general travel footage.
It also acts as a light shield for the lens, helping reduce fingerprints, dust, and minor surface marks. That extra protection is welcome on a dash cam lens that sits in a hot cabin and gets handled during installation, so what does that mean for long-term use?

Where it fits in the VIOFO lineup
Compared with a standard replacement lens cap or a no-name CPL ring, this accessory is more focused on image correction than simple protection. It is a better match for drivers who already care about footage quality and want to fine-tune a premium VIOFO camera rather than just cover the lens.
AliExpress UK-style buyers will appreciate that the value here comes from compatibility and optical function, not from bundled extras. With only two customer reviews available and both rating it highly, the early signal is positive, although the sample is still too small to treat as a full market verdict.
- Reduces windshield and dashboard glare
- Designed for VIOFO A329S, A229 Pro and A229 Plus
- Magnetic adsorption for fast installation
- Helps preserve natural colour balance
- Protects the lens from dust and fingerprints
- Improves contrast in bright daylight scenes

















