Hello, I have a '73 vert and I happened to notice a very thin, one-inch crack has appeared in the paint behind the chrome molding just behind the fabric top (please see pics). The paint is not original; the car received a medium- quality repaint about 15 years ago. Is there something I can inject into or paint over the crack to prevent it from spreading further? Could this be this the result of rust underneath (the car to this point has appeared to me to be rust-free)? Or, since it's in the vicinity of the top and the trunk, could the movement of the top going up and down (as well as the opening/closing of the trunk lid) be causing it? Or simply expansion/contraction of the paint over time? I know it's a tiny flaw but I've put my money, heart and soul into this car and I want to take whatever preventative measures I can to keep it nice for as long as I can. I should also mention that the car never sees water and is garaged for the entirety of the Fall and Winter.