I have the impression that cars and trucks were stored out of the weather when not in use, like in a garage, more so than what is done these days. My old friend who had an auto/truck repair shop that he opened in 1919 told me of how automobile paint durability improved over time until around the 1960's where a car could be left outside all of the time. In the '40's it was unwise to park you car in the sun, under a pecan tree, etc. Recommended storage was in a garage to prolong the life of the paint and I guess the wood in the pick up trucks too.
In this part of the country, an auto left out, uncovered, gets wet every day even if it's not raining. It's covered with dew every morning and doesn't dry off until the sun burns it off. My '46's paint is the same as when I got the truck three years ago since I store it out of the weather. A '55, 2nd series that I had, deteriorated badly in the same amount of time when I had no cover for it.
Jacques
