2 paint or not to paint

I tried to put myself in your place and come up with an answer. I came up with I don't know. If your intent is purely to retain its value, just put a cover on it and never drive it again. Every time you touch it, it will be different than it was. Wearing it out will also drop its value. If I put myself in my shoes, I would just drive it on nice days and have fun with it. The amount of value it would lose if you paint it, assuming you do a perfect job, and that it does actually lose value, is nothing compared to the actual cost to paint it.