Here's a macro image of a what a winter in Maine can do to your paint. During the cleaning process yesterday, one of the yearly tasks is to clay-bar the entire car. In this image you will see a Macro view of my passenger front door. I have cleaned the whole area except for the one spot outlined as "non-clay area". I also did a 5x zoom on that area to show how bad the road salt can eat and rust stain your clear coat if not protected and cleaned.
I started to notice that after a good wash, the car still had a yellow haze all over. As you can see, this was caused by the small rust spots in the clear. After 6 hours of using the clay bar, I was able to remove all of the rust and small tar spots to reveal the factory finish!
After the clay process, it is highly recommended to put on a coat of a high-quality sealer wax.