Short answer: fog is just a cloud that has lost altitude. Long answer: Because the humidity has reached more than 100% and the water starts to appear as vapour. You will also find that every outdoor...
The light assy come out fairly easy. you can either take the lamps out buy poping out the inboard side then there is a adjustment screw you can take out from the bottom. Also you can remove them by...
As far as I know, it's a load of miniscule water droplets suspended in the air because they are small and light enough to. It wouldn't be a gas, but a liquid that is so small that you can hardly see...