I can't say that it helped a lot in preventing the windows from getting too foggy, but it definitely helped in defogging them faster (for at least two to three weeks). Maybe I didn't apply enough quantity (the bottle doesn't specify anything specific). I will try it again and come back with feedback

Reduces condensation/fogging on the windows by at least 50-60%.
In the car, it leaves a slight haze (especially if you apply it with two hands), so it's better to stick to using one hand.
It is effective for use on household windows too!

I tried it on the bathroom mirror and it really does the job. I applied it on the car windows. They require a thorough cleaning before application.

Sometimes it leaves a stain on the glass that doesn't come off on its own. However, I believe that it's a matter of finding the right dosage for the size of the glass each time because whenever I use it correctly, it seems to do what it promises.

It does exactly what it promises.
I put it on all the windows of 2 cars and also on the bathroom mirrors and they hardly fog up at all.
The installation is very easy and the bottle lasts for 3 years.