I love sharing these story's that eventually have a happy ending and the problem is solved. I've seen fish eye problems being anything from a disgruntled employee that was fired and sprayed two cans of Armor-all down the air intake of the air make up unit, too a silicone based product being used on the inside of the car and all went well until the bake cycle was turned on to cure the paint. The temperature of the booth got up to 140 degrees causing the air inside the car to expand and the silicone saturated air in the cabin of the car moved out the vents, onto the car and fish eyed the hood.
One of my favorite fish eye story's (not unlike the KFC story) was a shop that once a month the shop would have fish eye problems only one or two cars and then, no problem. We couldn't figure out how or why. All we could do was try to figure out what the common theme was for the fish eyes and it turned out that it was coming from one prepper on the last day of every month. So we waited for the last day of the month to come around and it just so happened that the prepper's girl friend always came in at noon to pick up his pay check and he would show her what he was working on and she would feel how smooth the body work and his prepping was. As it turned out, she told us that she had a extremely dry skin and all the body shop dust made her skin that much drier so before she came to pick up her boyfriends pay check she would lather herself in hand lotion and body cream and just by feeling how smooth the panels where, she contaminated the panels.
Here is just another example of how important it is to have a clean uncontaminated environment and the reason for direct deposit is self explanatory.