You might be right. The focus might be a bit off.
Unfortunately, the license plate might not be visible in this image due to the angle of the sun.
The license plate being visible in any frame throughout the video is sufficient.
I was just trying to offer advice on whether there's a simple solution.
My final tip: check the lens's cleanliness.
As I mentioned, this camera doesn't have ventilation holes. I experienced the same issue after extended use. These feedbacks, including the fact that a compatible telephoto camera for the A329 series has ventilation holes, are proof of this.
This suggests your suspicions may be justified.
You can review my feedback below from top to bottom.
The vehicle leaves the garage and is parked in the sun. The camera has just been initialized.
The one on the left is the moment the recording starts. The one on the right is about 1 hour later..