Morning dew can be a problem or just moisture. That's why I hate winter. I detailed a car and left the SG on over night. Well the temp. dropped from 40o to 28o causing moisture to sit on the roof of the car. Not the hood or any other flat spot. When I went the next day(30 hrs later) the temp was 33o. Wasn't suppose to drop at all. Trust me it was a pain to get the SG off. I couldn't get it off with the PC, but I did with my favorite of all the Concours Buffing Towel. I was sweating my butt off.
Now I have my own garage and I would be able to control the moisture. I still have customers that want it done at there place.