Seems to be working!
It is not perfect on the rear dashcam, because your wind deflector is at the wrong angle. For reflected light to get fully polarised, the glass needs to be at about 45°, polarising filters don't do much at all for vertical glass. You have both 45° and almost vertical; it will remove reflections well off the rear window when the sun is lighting up your engine cover, or whatever is down there. It is not going to be great for the wind deflector reflections, which might be an issue with the roof down. You might be able to improve the wind deflector reflections by fitting some sort of lens hood around the camera, but that goes against you wanting a tiny dashcam.